Method for constructing preamble in wireless communication system

ABSTRACT

One embodiment according to the present specification relates to a method for constructing a preamble in a wireless LAN (WLAN) system. According to various embodiments, a PPDU may comprise a first signal field and a second signal field. The first signal field may include first information about PHY version. The first information may be determined on the basis of whether the PPDU is an EHT PPDU. The second signal field may include second information about the transmission of the PPDU, which is set on the basis of the first information.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.17/775,248, filed on May 6, 2022, which is the National Stage filingunder 35 U.S.C. 371 of International Application No. PCT/KR2020/015623,filed on Nov. 9, 2020, which claims the benefit of U.S. ProvisionalApplication No. 62/933,381, filed on Nov. 9, 2019, and also claims thebenefit of earlier filing date and right of priority to KoreanApplication Nos. 10-2019-0156968, filed on Nov. 29, 2019,10-2019-0163057, filed on Dec. 9, 2019, 10-2019-0165063, filed on Dec.11, 2019, 10-2019-0166041, filed on Dec. 12, 2019, 10-2019-0168226,filed on Dec. 16, 2019, and 10-2020-0023187, filed on Feb. 25, 2020, thecontents of which are all incorporated by reference herein in theirentirety.

FIELD OF THE DISCLOSURE

This specification relates to a technique for configuring a preamble ina wireless LAN system, and more particularly, to a method forconfiguring a preamble in a wireless LAN system and an apparatussupporting the same.

RELATED ART

A wireless local area network (WLAN) has been enhanced in various ways.For example, the IEEE 802.11ax standard has proposed an enhancedcommunication environment by using orthogonal frequency divisionmultiple access (OFDMA) and downlink multi-user multiple input multipleoutput (DL MU MIMO) schemes.

The present specification proposes a technical feature that can beutilized in a new communication standard. For example, the newcommunication standard may be an extreme high throughput (EHT) standardwhich is currently being discussed. The EHT standard may use anincreased bandwidth, an enhanced PHY layer protocol data unit (PPDU)structure, an enhanced sequence, a hybrid automatic repeat request(HARQ) scheme, or the like, which is newly proposed. The EHT standardmay be called the IEEE 802.11be standard.

SUMMARY Technical Objects

In the EHT standard, in order to support high throughput and high datarate, a wide bandwidth (e.g., 160/320 MHz), 16 streams, and/ormulti-link (or multi-band) operation may be used. Accordingly, a newframe format may be used to support the transmission method (oroperation). When the EHT signal of the new frame format is transmittedthrough the 2.4 GHz/5 GHz/6 GHz band, not only the EHT standard receiverbut also convention Wi-Fi receivers (e.g., 802.11n, 802.11ac, 802.11axstandard STA) may receive the EHT signal transmitted through the band.In this case, a field for supporting backward compatibility withconventional Wi-Fi and early indication of an EHT signal may berequired.

Technical Solutions

According to various embodiments, a receiving station (STA) may receivea Physical Layer Protocol Data Unit (PPDU).

According to various embodiments, the PPDU includes a first signal fieldand a second signal field, the first signal field is transmitted throughtwo symbols, the first signal field includes first information relatedto a Physical layer (PHY) version of the PPDU, the first information isdetermined based on whether the PPDU is an extremely high throughput(EHT) PPDU, and the second signal field includes second informationwhich is related to transmission of the PPDU configured based on thefirst information.

According to various embodiments, the receiving STA may decode the PPDUbased on the first signal field and the second signal field.

Technical Effects of the Disclosure

According to various embodiments, the PPDU may include a first signalfield and a second signal field.

According to various embodiments, the receiving STA may identify aversion of the received PPDU based on the first signal field. Thereceiving STA may confirm/check that the received PPDU is an EHT PPDUbased on the first signal field.

According to various embodiments, the second signal field may includeinformation related to PPDU transmission. Accordingly, there is aneffect that the receiving STA can quickly check information related toPPDU transmission based on the second signal field.

According to various embodiments, the PPDU may be configured andtransmitted for a single user and multiple users. Accordingly, there isan effect that PPDUs having the same configuration can be transmittedfor a single user and multiple users.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an example of a transmitting apparatus and/or receivingapparatus of the present specification.

FIG. 2 is a conceptual view illustrating the structure of a wirelesslocal area network (WLAN).

FIG. 3 illustrates a general link setup process.

FIG. 4 illustrates an example of a PPDU used in an IEEE standard.

FIG. 5 illustrates a layout of resource units (RUs) used in a band of 20MHz.

FIG. 6 illustrates a layout of RUs used in a band of 40 MHz.

FIG. 7 illustrates a layout of RUs used in a band of 80 MHz.

FIG. 8 illustrates a structure of an HE-SIG-B field.

FIG. 9 illustrates an example in which a plurality of user STAs areallocated to the same RU through a MU-MIMO scheme.

FIG. 10 illustrates an operation based on UL-MU.

FIG. 11 illustrates an example of a trigger frame.

FIG. 12 illustrates an example of a common information field of atrigger frame.

FIG. 13 illustrates an example of a subfield included in a per userinformation field.

FIG. 14 describes a technical feature of the UORA scheme.

FIG. 15 illustrates an example of a channel used/supported/definedwithin a 2.4 GHz band.

FIG. 16 illustrates an example of a channel used/supported/definedwithin a 5 GHz band.

FIG. 17 illustrates an example of a channel used/supported/definedwithin a 6 GHz band.

FIG. 18 illustrates an example of a PPDU used in the presentspecification.

FIG. 19 illustrates an example of a modified transmitting device and/orreceiving device of the present specification.

FIG. 20 shows an example of an EHT PPDU.

FIG. 21 shows an example of an EHT signal field.

FIG. 22 shows an example of the configuration of an SU PPDU.

FIG. 23 shows another example of the configuration of an SU PPDU.

FIG. 24 shows an example of the configuration of an MU PPDU.

FIG. 25 shows another example of the configuration of an MU PPDU.

FIG. 26 shows an example of the configuration of a TB PPDU.

FIG. 27 shows another example of the configuration of a TB PPDU.

FIG. 28 shows an example of the configuration of an ER SU PPDU.

FIG. 29 shows another example of the configuration of an ER SU PPDU.

FIG. 30 shows another example of the configuration of an ER SU PPDU.

FIG. 31 is a flowchart for explaining an operation of a transmittingSTA.

FIG. 32 is a flowchart illustrating an operation of a receiving STA.

DETAILED DESCRIPTION

In the present specification, “A or B” may mean “only A”, “only B” or“both A and B”. In other words, in the present specification, “A or B”may be interpreted as “A and/or B”. For example, in the presentspecification, “A, B, or C” may mean “only A”, “only B”, “only C”, or“any combination of A, B, C”.

A slash (/) or comma used in the present specification may mean“and/or”. For example, “A/B” may mean “A and/or B”. Accordingly, “A/B”may mean “only A”, “only B”, or “both A and B”. For example, “A, B, C”may mean “A, B, or C”.

In the present specification, “at least one of A and B” may mean “onlyA”, “only B”, or “both A and B”. In addition, in the presentspecification, the expression “at least one of A or B” or “at least oneof A and/or B” may be interpreted as “at least one of A and B”.

In addition, in the present specification, “at least one of A, B, and C”may mean “only A”, “only B”, “only C”, or “any combination of A, B, andC”. In addition, “at least one of A, B, or C” or “at least one of A, B,and/or C” may mean “at least one of A, B, and C”.

In addition, a parenthesis used in the present specification may mean“for example”. Specifically, when indicated as “control information(EHT-signal)”, it may mean that “EHT-signal” is proposed as an exampleof the “control information”. In other words, the “control information”of the present specification is not limited to “EHT-signal”, and“EHT-signal” may be proposed as an example of the “control information”.In addition, when indicated as “control information (i.e., EHT-signal)”,it may also mean that “EHT-signal” is proposed as an example of the“control information”.

Technical features described individually in one figure in the presentspecification may be individually implemented, or may be simultaneouslyimplemented.

The following example of the present specification may be applied tovarious wireless communication systems. For example, the followingexample of the present specification may be applied to a wireless localarea network (WLAN) system. For example, the present specification maybe applied to the IEEE 802.11a/g/n/ac standard or the IEEE 802.11axstandard. In addition, the present specification may also be applied tothe newly proposed EHT standard or IEEE 802.11be standard. In addition,the example of the present specification may also be applied to a newWLAN standard enhanced from the EHT standard or the IEEE 802.11bestandard. In addition, the example of the present specification may beapplied to a mobile communication system. For example, it may be appliedto a mobile communication system based on long term evolution (LTE)depending on a 3rd generation partnership project (3GPP) standard andbased on evolution of the LTE. In addition, the example of the presentspecification may be applied to a communication system of a 5G NRstandard based on the 3GPP standard.

Hereinafter, in order to describe a technical feature of the presentspecification, a technical feature applicable to the presentspecification will be described.

FIG. 1 shows an example of a transmitting apparatus and/or receivingapparatus of the present specification.

In the example of FIG. 1 , various technical features described belowmay be performed. FIG. 1 relates to at least one station (STA). Forexample, STAs 110 and 120 of the present specification may also becalled in various terms such as a mobile terminal, a wireless device, awireless transmit/receive unit (WTRU), a user equipment (UE), a mobilestation (MS), a mobile subscriber unit, or simply a user. The STAs 110and 120 of the present specification may also be called in various termssuch as a network, a base station, a node-B, an access point (AP), arepeater, a router, a relay, or the like. The STAs 110 and 120 of thepresent specification may also be referred to as various names such as areceiving apparatus, a transmitting apparatus, a receiving STA, atransmitting STA, a receiving device, a transmitting device, or thelike.

For example, the STAs 110 and 120 may serve as an AP or a non-AP. Thatis, the STAs 110 and 120 of the present specification may serve as theAP and/or the non-AP.

The STAs 110 and 120 of the present specification may support variouscommunication standards together in addition to the IEEE 802.11standard. For example, a communication standard (e.g., LTE, LTE-A, 5G NRstandard) or the like based on the 3GPP standard may be supported. Inaddition, the STA of the present specification may be implemented asvarious devices such as a mobile phone, a vehicle, a personal computer,or the like. In addition, the STA of the present specification maysupport communication for various communication services such as voicecalls, video calls, data communication, and self-driving(autonomous-driving), or the like.

The STAs 110 and 120 of the present specification may include a mediumaccess control (MAC) conforming to the IEEE 802.11 standard and aphysical layer interface for a radio medium.

The STAs 110 and 120 will be described below with reference to asub-figure (a) of FIG. 1 .

The first STA 110 may include a processor 111, a memory 112, and atransceiver 113. The illustrated process, memory, and transceiver may beimplemented individually as separate chips, or at least twoblocks/functions may be implemented through a single chip.

The transceiver 113 of the first STA performs a signaltransmission/reception operation. Specifically, an IEEE 802.11 packet(e.g., IEEE 802.11a/b/g/n/ac/ax/be, etc.) may be transmitted/received.

For example, the first STA 110 may perform an operation intended by anAP. For example, the processor 111 of the AP may receive a signalthrough the transceiver 113, process a reception (RX) signal, generate atransmission (TX) signal, and provide control for signal transmission.The memory 112 of the AP may store a signal (e.g., RX signal) receivedthrough the transceiver 113, and may store a signal (e.g., TX signal) tobe transmitted through the transceiver.

For example, the second STA 120 may perform an operation intended by anon-AP STA. For example, a transceiver 123 of a non-AP performs a signaltransmission/reception operation. Specifically, an IEEE 802.11 packet(e.g., IEEE 802.11a/b/g/n/ac/ax/be packet, etc.) may betransmitted/received.

For example, a processor 121 of the non-AP STA may receive a signalthrough the transceiver 123, process an RX signal, generate a TX signal,and provide control for signal transmission. A memory 122 of the non-APSTA may store a signal (e.g., RX signal) received through thetransceiver 123, and may store a signal (e.g., TX signal) to betransmitted through the transceiver.

For example, an operation of a device indicated as an AP in thespecification described below may be performed in the first STA 110 orthe second STA 120. For example, if the first STA 110 is the AP, theoperation of the device indicated as the AP may be controlled by theprocessor 111 of the first STA 110, and a related signal may betransmitted or received through the transceiver 113 controlled by theprocessor 111 of the first STA 110. In addition, control informationrelated to the operation of the AP or a TX/RX signal of the AP may bestored in the memory 112 of the first STA 110. In addition, if thesecond STA 120 is the AP, the operation of the device indicated as theAP may be controlled by the processor 121 of the second STA 120, and arelated signal may be transmitted or received through the transceiver123 controlled by the processor 121 of the second STA 120. In addition,control information related to the operation of the AP or a TX/RX signalof the AP may be stored in the memory 122 of the second STA 120.

For example, in the specification described below, an operation of adevice indicated as a non-AP (or user-STA) may be performed in the firstSTA 110 or the second STA 120. For example, if the second STA 120 is thenon-AP, the operation of the device indicated as the non-AP may becontrolled by the processor 121 of the second STA 120, and a relatedsignal may be transmitted or received through the transceiver 123controlled by the processor 121 of the second STA 120. In addition,control information related to the operation of the non-AP or a TX/RXsignal of the non-AP may be stored in the memory 122 of the second STA120. For example, if the first STA 110 is the non-AP, the operation ofthe device indicated as the non-AP may be controlled by the processor111 of the first STA 110, and a related signal may be transmitted orreceived through the transceiver 113 controlled by the processor 111 ofthe first STA 110. In addition, control information related to theoperation of the non-AP or a TX/RX signal of the non-AP may be stored inthe memory 112 of the first STA 110.

In the specification described below, a device called a(transmitting/receiving) STA, a first STA, a second STA, a STA1, a STA2,an AP, a first AP, a second AP, an AP1, an AP2, a(transmitting/receiving) terminal, a (transmitting/receiving) device, a(transmitting/receiving) apparatus, a network, or the like may imply theSTAs 110 and 120 of FIG. 1 . For example, a device indicated as, withouta specific reference numeral, the (transmitting/receiving) STA, thefirst STA, the second STA, the STA1, the STA2, the AP, the first AP, thesecond AP, the AP1, the AP2, the (transmitting/receiving) terminal, the(transmitting/receiving) device, the (transmitting/receiving) apparatus,the network, or the like may imply the STAs 110 and 120 of FIG. 1 . Forexample, in the following example, an operation in which various STAstransmit/receive a signal (e.g., a PPDU) may be performed in thetransceivers 113 and 123 of FIG. 1 . In addition, in the followingexample, an operation in which various STAs generate a TX/RX signal orperform data processing and computation in advance for the TX/RX signalmay be performed in the processors 111 and 121 of FIG. 1 . For example,an example of an operation for generating the TX/RX signal or performingthe data processing and computation in advance may include: 1) anoperation ofdetermining/obtaining/configuring/computing/decoding/encoding bitinformation of a sub-field (SIG, STF, LTF, Data) included in a PPDU; 2)an operation of determining/configuring/obtaining a time resource orfrequency resource (e.g., a subcarrier resource) or the like used forthe sub-field (SIG, STF, LTF, Data) included the PPDU; 3) an operationof determining/configuring/obtaining a specific sequence (e.g., a pilotsequence, an STF/LTF sequence, an extra sequence applied to SIG) or thelike used for the sub-field (SIG, STF, LTF, Data) field included in thePPDU; 4) a power control operation and/or power saving operation appliedfor the STA; and 5) an operation related todetermining/obtaining/configuring/decoding/encoding or the like of anACK signal. In addition, in the following example, a variety ofinformation used by various STAs fordetermining/obtaining/configuring/computing/decoding/decoding a TX/RXsignal (e.g., information related to a field/subfield/controlfield/parameter/power or the like) may be stored in the memories 112 and122 of FIG. 1 .

The aforementioned device/STA of the sub-figure (a) of FIG. 1 may bemodified as shown in the sub-figure (b) of FIG. 1 . Hereinafter, theSTAs 110 and 120 of the present specification will be described based onthe sub-figure (b) of FIG. 1 .

For example, the transceivers 113 and 123 illustrated in the sub-figure(b) of FIG. 1 may perform the same function as the aforementionedtransceiver illustrated in the sub-figure (a) of FIG. 1 . For example,processing chips 114 and 124 illustrated in the sub-figure (b) of FIG. 1may include the processors 111 and 121 and the memories 112 and 122. Theprocessors 111 and 121 and memories 112 and 122 illustrated in thesub-figure (b) of FIG. 1 may perform the same function as theaforementioned processors 111 and 121 and memories 112 and 122illustrated in the sub-figure (a) of FIG. 1 .

A mobile terminal, a wireless device, a wireless transmit/receive unit(WTRU), a user equipment (UE), a mobile station (MS), a mobilesubscriber unit, a user, a user STA, a network, a base station, aNode-B, an access point (AP), a repeater, a router, a relay, a receivingunit, a transmitting unit, a receiving STA, a transmitting STA, areceiving device, a transmitting device, a receiving apparatus, and/or atransmitting apparatus, which are described below, may imply the STAs110 and 120 illustrated in the sub-figure (a)/(b) of FIG. 1 , or mayimply the processing chips 114 and 124 illustrated in the sub-figure (b)of FIG. 1 . That is, a technical feature of the present specificationmay be performed in the STAs 110 and 120 illustrated in the sub-figure(a)/(b) of FIG. 1 , or may be performed only in the processing chips 114and 124 illustrated in the sub-figure (b) of FIG. 1 . For example, atechnical feature in which the transmitting STA transmits a controlsignal may be understood as a technical feature in which a controlsignal generated in the processors 111 and 121 illustrated in thesub-figure (a)/(b) of FIG. 1 is transmitted through the transceivers 113and 123 illustrated in the sub-figure (a)/(b) of FIG. 1 . Alternatively,the technical feature in which the transmitting STA transmits thecontrol signal may be understood as a technical feature in which thecontrol signal to be transferred to the transceivers 113 and 123 isgenerated in the processing chips 114 and 124 illustrated in thesub-figure (b) of FIG. 1 .

For example, a technical feature in which the receiving STA receives thecontrol signal may be understood as a technical feature in which thecontrol signal is received by means of the transceivers 113 and 123illustrated in the sub-figure (a) of FIG. 1 . Alternatively, thetechnical feature in which the receiving STA receives the control signalmay be understood as the technical feature in which the control signalreceived in the transceivers 113 and 123 illustrated in the sub-figure(a) of FIG. 1 is obtained by the processors 111 and 121 illustrated inthe sub-figure (a) of FIG. 1 . Alternatively, the technical feature inwhich the receiving STA receives the control signal may be understood asthe technical feature in which the control signal received in thetransceivers 113 and 123 illustrated in the sub-figure (b) of FIG. 1 isobtained by the processing chips 114 and 124 illustrated in thesub-figure (b) of FIG. 1 .

Referring to the sub-figure (b) of FIG. 1 , software codes 115 and 125may be included in the memories 112 and 122. The software codes 115 and126 may include instructions for controlling an operation of theprocessors 111 and 121. The software codes 115 and 125 may be includedas various programming languages.

The processors 111 and 121 or processing chips 114 and 124 of FIG. 1 mayinclude an application-specific integrated circuit (ASIC), otherchipsets, a logic circuit and/or a data processing device. The processormay be an application processor (AP). For example, the processors 111and 121 or processing chips 114 and 124 of FIG. 1 may include at leastone of a digital signal processor (DSP), a central processing unit(CPU), a graphics processing unit (GPU), and a modulator and demodulator(modem). For example, the processors 111 and 121 or processing chips 114and 124 of FIG. 1 may be SNAPDRAGON™ series of processors made byQualcomm®, EXYNOS™ series of processors made by Samsung®, A series ofprocessors made by Apple®, HELIO™ series of processors made byMediaTek®, ATOM™ series of processors made by Intel® or processorsenhanced from these processors.

In the present specification, an uplink may imply a link forcommunication from a non-AP STA to an SP STA, and an uplinkPPDU/packet/signal or the like may be transmitted through the uplink. Inaddition, in the present specification, a downlink may imply a link forcommunication from the AP STA to the non-AP STA, and a downlinkPPDU/packet/signal or the like may be transmitted through the downlink.

FIG. 2 is a conceptual view illustrating the structure of a wirelesslocal area network (WLAN).

An upper part of FIG. 2 illustrates the structure of an infrastructurebasic service set (BSS) of institute of electrical and electronicengineers (IEEE) 802.11.

Referring the upper part of FIG. 2 , the wireless LAN system may includeone or more infrastructure BSSs 200 and 205 (hereinafter, referred to asBSS). The BSSs 200 and 205 as a set of an AP and a STA such as an accesspoint (AP) 225 and a station (STA1) 200-1 which are successfullysynchronized to communicate with each other are not concepts indicatinga specific region. The BSS 205 may include one or more STAs 205-1 and205-2 which may be joined to one AP 230.

The BSS may include at least one STA, APs providing a distributionservice, and a distribution system (DS) 210 connecting multiple APs.

The distribution system 210 may implement an extended service set (ESS)240 extended by connecting the multiple BSSs 200 and 205. The ESS 240may be used as a term indicating one network configured by connectingone or more APs 225 or 230 through the distribution system 210. The APincluded in one ESS 240 may have the same service set identification(SSID).

A portal 220 may serve as a bridge which connects the wireless LANnetwork (IEEE 802.11) and another network (e.g., 802.X).

In the BSS illustrated in the upper part of FIG. 2 , a network betweenthe APs 225 and 230 and a network between the APs 225 and 230 and theSTAs 200-1, 205-1, and 205-2 may be implemented. However, the network isconfigured even between the STAs without the APs 225 and 230 to performcommunication. A network in which the communication is performed byconfiguring the network even between the STAs without the APs 225 and230 is defined as an Ad-Hoc network or an independent basic service set(IBSS).

A lower part of FIG. 2 illustrates a conceptual view illustrating theIBSS.

Referring to the lower part of FIG. 2 , the IBSS is a BSS that operatesin an Ad-Hoc mode. Since the IBSS does not include the access point(AP), a centralized management entity that performs a managementfunction at the center does not exist. That is, in the IBSS, STAs 250-1,250-2, 250-3, 255-4, and 255-5 are managed by a distributed manner. Inthe IBSS, all STAs 250-1, 250-2, 250-3, 255-4, and 255-5 may beconstituted by movable STAs and are not permitted to access the DS toconstitute a self-contained network.

FIG. 3 illustrates a general link setup process.

In S310, a STA may perform a network discovery operation. The networkdiscovery operation may include a scanning operation of the STA. Thatis, to access a network, the STA needs to discover a participatingnetwork. The STA needs to identify a compatible network beforeparticipating in a wireless network, and a process of identifying anetwork present in a particular area is referred to as scanning.Scanning methods include active scanning and passive scanning.

FIG. 3 illustrates a network discovery operation including an activescanning process. In active scanning, a STA performing scanningtransmits a probe request frame and waits for a response to the proberequest frame in order to identify which AP is present around whilemoving to channels. A responder transmits a probe response frame as aresponse to the probe request frame to the STA having transmitted theprobe request frame. Here, the responder may be a STA that transmits thelast beacon frame in a BSS of a channel being scanned. In the BSS, sincean AP transmits a beacon frame, the AP is the responder. In an IBSS,since STAs in the IBSS transmit a beacon frame in turns, the responderis not fixed. For example, when the STA transmits a probe request framevia channel 1 and receives a probe response frame via channel 1, the STAmay store BSS-related information included in the received proberesponse frame, may move to the next channel (e.g., channel 2), and mayperform scanning (e.g., transmits a probe request and receives a proberesponse via channel 2) by the same method.

Although not shown in FIG. 3 , scanning may be performed by a passivescanning method. In passive scanning, a STA performing scanning may waitfor a beacon frame while moving to channels. A beacon frame is one ofmanagement frames in IEEE 802.11 and is periodically transmitted toindicate the presence of a wireless network and to enable the STAperforming scanning to find the wireless network and to participate inthe wireless network. In a BSS, an AP serves to periodically transmit abeacon frame. In an IBSS, STAs in the IBSS transmit a beacon frame inturns. Upon receiving the beacon frame, the STA performing scanningstores information related to a BSS included in the beacon frame andrecords beacon frame information in each channel while moving to anotherchannel. The STA having received the beacon frame may store BSS-relatedinformation included in the received beacon frame, may move to the nextchannel, and may perform scanning in the next channel by the samemethod.

After discovering the network, the STA may perform an authenticationprocess in S320. The authentication process may be referred to as afirst authentication process to be clearly distinguished from thefollowing security setup operation in S340. The authentication processin S320 may include a process in which the STA transmits anauthentication request frame to the AP and the AP transmits anauthentication response frame to the STA in response. The authenticationframes used for an authentication request/response are managementframes.

The authentication frames may include information related to anauthentication algorithm number, an authentication transaction sequencenumber, a status code, a challenge text, a robust security network(RSN), and a finite cyclic group.

The STA may transmit the authentication request frame to the AP. The APmay determine whether to allow the authentication of the STA based onthe information included in the received authentication request frame.The AP may provide the authentication processing result to the STA viathe authentication response frame.

When the STA is successfully authenticated, the STA may perform anassociation process in S330. The association process includes a processin which the STA transmits an association request frame to the AP andthe AP transmits an association response frame to the STA in response.The association request frame may include, for example, informationrelated to various capabilities, a beacon listen interval, a service setidentifier (SSID), a supported rate, a supported channel, RSN, amobility domain, a supported operating class, a traffic indication map(TIM) broadcast request, and an interworking service capability. Theassociation response frame may include, for example, information relatedto various capabilities, a status code, an association ID (AID), asupported rate, an enhanced distributed channel access (EDCA) parameterset, a received channel power indicator (RCPI), a receivedsignal-to-noise indicator (RSNI), a mobility domain, a timeout interval(association comeback time), an overlapping BSS scanning parameter, aTIM broadcast response, and a QoS map.

In S340, the STA may perform a security setup process. The securitysetup process in S340 may include a process of setting up a private keythrough four-way handshaking, for example, through an extensibleauthentication protocol over LAN (EAPOL) frame.

FIG. 4 illustrates an example of a PPDU used in an IEEE standard. Asillustrated, various types of PHY protocol data units (PPDUs) are usedin IEEE a/g/n/ac standards. Specifically, an LTF and a STF include atraining signal, a SIG-A and a SIG-B include control information for areceiving STA, and a data field includes user data corresponding to aPSDU (MAC PDU/aggregated MAC PDU).

FIG. 4 also includes an example of an HE PPDU according to IEEE802.11ax. The HE PPDU according to FIG. 4 is an illustrative PPDU formultiple users. An HE-SIG-B may be included only in a PPDU for multipleusers, and an HE-SIG-B may be omitted in a PPDU for a single user.

As illustrated in FIG. 4 , the HE-PPDU for multiple users (MUs) mayinclude a legacy-short training field (L-STF), a legacy-long trainingfield (L-LTF), a legacy-signal (L-SIG), a high efficiency-signal A(HE-SIG A), a high efficiency-signal-B (HE-SIG B), a highefficiency-short training field (HE-STF), a high efficiency-longtraining field (HE-LTF), a data field (alternatively, an MAC payload),and a packet extension (PE) field. The respective fields may betransmitted for illustrated time periods (i.e., 4 or 8 μs).

Hereinafter, a resource unit (RU) used for a PPDU is described. An RUmay include a plurality of subcarriers (or tones). An RU may be used totransmit a signal to a plurality of STAs according to OFDMA. Further, anRU may also be defined to transmit a signal to one STA. An RU may beused for an STF, an LTF, a data field, or the like.

FIG. 5 illustrates a layout of resource units (RUs) used in a band of 20MHz.

As illustrated in FIG. 5 , resource units (RUs) corresponding todifferent numbers of tones (i.e., subcarriers) may be used to form somefields of an HE-PPDU. For example, resources may be allocated inillustrated RUs for an HE-STF, an HE-LTF, and a data field.

As illustrated in the uppermost part of FIG. 5 , a 26-unit (i.e., a unitcorresponding to 26 tones) may be disposed. Six tones may be used for aguard band in the leftmost band of the 20 MHz band, and five tones maybe used for a guard band in the rightmost band of the 20 MHz band.Further, seven DC tones may be inserted in a center band, that is, a DCband, and a 26-unit corresponding to 13 tones on each of the left andright sides of the DC band may be disposed. A 26-unit, a 52-unit, and a106-unit may be allocated to other bands. Each unit may be allocated fora receiving STA, that is, a user.

The layout of the RUs in FIG. 5 may be used not only for a multipleusers (MUs) but also for a single user (SU), in which case one 242-unitmay be used and three DC tones may be inserted as illustrated in thelowermost part of FIG. 5 .

Although FIG. 5 proposes RUs having various sizes, that is, a 26-RU, a52-RU, a 106-RU, and a 242-RU, specific sizes of RUs may be extended orincreased. Therefore, the present embodiment is not limited to thespecific size of each RU (i.e., the number of corresponding tones).

FIG. 6 illustrates a layout of RUs used in a band of 40 MHz.

Similarly to FIG. 5 in which RUs having various sizes are used, a 26-RU,a 52-RU, a 106-RU, a 242-RU, a 484-RU, and the like may be used in anexample of FIG. 6 . Further, five DC tones may be inserted in a centerfrequency, 12 tones may be used for a guard band in the leftmost band ofthe 40 MHz band, and 11 tones may be used for a guard band in therightmost band of the 40 MHz band.

As illustrated in FIG. 6 , when the layout of the RUs is used for asingle user, a 484-RU may be used. The specific number of RUs may bechanged similarly to FIG. 5 .

FIG. 7 illustrates a layout of RUs used in a band of 80 MHz.

Similarly to FIG. 5 and FIG. 6 in which RUs having various sizes areused, a 26-RU, a 52-RU, a 106-RU, a 242-RU, a 484-RU, a 996-RU, and thelike may be used in an example of FIG. 7 . Further, seven DC tones maybe inserted in the center frequency, 12 tones may be used for a guardband in the leftmost band of the 80 MHz band, and 11 tones may be usedfor a guard band in the rightmost band of the 80 MHz band. In addition,a 26-RU corresponding to 13 tones on each of the left and right sides ofthe DC band may be used.

As illustrated in FIG. 7 , when the layout of the RUs is used for asingle user, a 996-RU may be used, in which case five DC tones may beinserted.

The RU described in the present specification may be used in uplink (UL)communication and downlink (DL) communication. For example, when UL-MUcommunication which is solicited by a trigger frame is performed, atransmitting STA (e.g., an AP) may allocate a first RU (e.g.,26/52/106/242-RU, etc.) to a first STA through the trigger frame, andmay allocate a second RU (e.g., 26/52/106/242-RU, etc.) to a second STA.Thereafter, the first STA may transmit a first trigger-based PPDU basedon the first RU, and the second STA may transmit a second trigger-basedPPDU based on the second RU. The first/second trigger-based PPDU istransmitted to the AP at the same (or overlapped) time period.

For example, when a DL MU PPDU is configured, the transmitting STA(e.g., AP) may allocate the first RU (e.g., 26/52/106/242-RU. etc.) tothe first STA, and may allocate the second RU (e.g., 26/52/106/242-RU,etc.) to the second STA. That is, the transmitting STA (e.g., AP) maytransmit HE-STF, HE-LTF, and Data fields for the first STA through thefirst RU in one MU PPDU, and may transmit HE-STF, HE-LTF, and Datafields for the second STA through the second RU.

Information related to a layout of the RU may be signaled throughHE-SIG-B.

FIG. 8 illustrates a structure of an HE-SIG-B field.

As illustrated, an HE-SIG-B field 810 includes a common field 820 and auser-specific field 830. The common field 820 may include informationcommonly applied to all users (i.e., user STAs) which receive SIG-B. Theuser-specific field 830 may be called a user-specific control field.When the SIG-B is transferred to a plurality of users, the user-specificfield 830 may be applied only any one of the plurality of users.

As illustrated in FIG. 8 , the common field 820 and the user-specificfield 830 may be separately encoded.

The common field 820 may include RU allocation information of N*8 bits.For example, the RU allocation information may include informationrelated to a location of an RU. For example, when a 20 MHz channel isused as shown in FIG. 5 , the RU allocation information may includeinformation related to a specific frequency band to which a specific RU(26-RU/52-RU/106-RU) is arranged.

An example of a case in which the RU allocation information consists of8 bits is as follows.

TABLE 1 8 bits indices (B7 B6 B5 B4 Number B3 B2 B1 B0) #1 #2 #3 #4 #5#6 #7 #8 #9 of entries 00000000 26 26 26 26 26 26 26 26 26 1 00000001 2626 26 26 26 26 26 52 00000010 26 26 26 26 26 52 26 26 1 00000011 26 2626 26 26 52 52 1 00000100 26 26 52 26 26 26 26 26 1 00000101 26 26 52 2626 26 52 1 00000110 26 26 52 26 52 26 26 1 00000111 26 26 52 26 52 52 100001000 52 26 26 26 26 26 26 26 1

As shown the example of FIG. 5 , up to nine 26-RUs may be allocated tothe 20 MHz channel. When the RU allocation information of the commonfield 820 is set to “00000000” as shown in Table 1, the nine 26-RUs maybe allocated to a corresponding channel (i.e., 20 MHz). In addition,when the RU allocation information of the common field 820 is set to“00000001” as shown in Table 1, seven 26-RUs and one 52-RU are arrangedin a corresponding channel. That is, in the example of FIG. 5 , the52-RU may be allocated to the rightmost side, and the seven 26-RUs maybe allocated to the left thereof.

The example of Table 1 shows only some of RU locations capable ofdisplaying the RU allocation information.

For example, the RU allocation information may include an example ofTable 2 below.

TABLE 2 8 bits indices (B7 B6 B5 B4 Number B3 B2 B1 B0) #1 #2 #3 #4 #5#6 #7 #8 #9 of entries 01000y₂y₁y₀ 106 26 26 26 26 26 8 01001y₂y₁y₀ 10626 26 26 52 8

“01000y2y1y0” relates to an example in which a 106-RU is allocated tothe leftmost side of the 20 MHz channel, and five 26-RUs are allocatedto the right side thereof. In this case, a plurality of STAs (e.g.,user-STAs) may be allocated to the 106-RU, based on a MU-MIMO scheme.Specifically, up to 8 STAs (e.g., user-STAs) may be allocated to the106-RU, and the number of STAs (e.g., user-STAs) allocated to the 106-RUis determined based on 3-bit information (y2y1y0). For example, when the3-bit information (y2y1y0) is set to N, the number of STAs (e.g.,user-STAs) allocated to the 106-RU based on the MU-MIMO scheme may beN+1.

In general, a plurality of STAs (e.g., user STAs) different from eachother may be allocated to a plurality of RUs. However, the plurality ofSTAs (e.g., user STAs) may be allocated to one or more RUs having atleast a specific size (e.g., 106 subcarriers), based on the MU-MIMOscheme.

As shown in FIG. 8 , the user-specific field 830 may include a pluralityof user fields. As described above, the number of STAs (e.g., user STAs)allocated to a specific channel may be determined based on the RUallocation information of the common field 820. For example, when the RUallocation information of the common field 820 is “00000000”, one userSTA may be allocated to each of nine 26-RUs (e.g., nine user STAs may beallocated). That is, up to 9 user STAs may be allocated to a specificchannel through an OFDMA scheme. In other words, up to 9 user STAs maybe allocated to a specific channel through a non-MU-MIMO scheme.

For example, when RU allocation is set to “01000y2y1y0”, a plurality ofSTAs may be allocated to the 106-RU arranged at the leftmost sidethrough the MU-MIMO scheme, and five user STAs may be allocated to five26-RUs arranged to the right side thereof through the non-MU MIMOscheme. This case is specified through an example of FIG. 9 .

FIG. 9 illustrates an example in which a plurality of user STAs areallocated to the same RU through a MU-MIMO scheme.

For example, when RU allocation is set to “01000010” as shown in FIG. 9, a 106-RU may be allocated to the leftmost side of a specific channel,and five 26-RUs may be allocated to the right side thereof. In addition,three user STAs may be allocated to the 106-RU through the MU-MIMOscheme. As a result, since eight user STAs are allocated, theuser-specific field 830 of HE-SIG-B may include eight user fields.

The eight user fields may be expressed in the order shown in FIG. 9 . Inaddition, as shown in FIG. 8 , two user fields may be implemented withone user block field.

The user fields shown in FIG. 8 and FIG. 9 may be configured based ontwo formats. That is, a user field related to a MU-MIMO scheme may beconfigured in a first format, and a user field related to a non-MIMOscheme may be configured in a second format. Referring to the example ofFIG. 9 , a user field 1 to a user field 3 may be based on the firstformat, and a user field 4 to a user field 8 may be based on the secondformat. The first format or the second format may include bitinformation of the same length (e.g., 21 bits).

Each user field may have the same size (e.g., 21 bits). For example, theuser field of the first format (the first of the MU-MIMO scheme) may beconfigured as follows.

For example, a first bit (i.e., B0-B10) in the user field (i.e., 21bits) may include identification information (e.g., STA-ID, partial AID,etc.) of a user STA to which a corresponding user field is allocated. Inaddition, a second bit (i.e., B11-B14) in the user field (i.e., 21 bits)may include information related to a spatial configuration.Specifically, an example of the second bit (i.e., B11-B14) may be asshown in Table 3 and Table 4 below.

TABLE 3 N_(STS) N_(STS) N_(STS) N_(STS) N_(STS) N_(STS) N_(STS) N_(STS)Total Number N_(user) B3 . . . B0 [1] [2] [3] [4] [5] [6] [7] [8]N_(STS) of entries 2 0000-0011 1-4 1 2-5 10 0100-0110 2-4 2 4-60111-1000 3-4 3 6-7 1001 4 4 8 3 0000-0011 1-4 1 1 3-6 13 0100-0110 2-42 1 5-7 0111-1000 3-4 3 1 7-8 1001-1011 2-4 2 2 6-8 1100 3 3 2 8 40000-0011 1-4 1 1 1 4-7 11 0100-0110 2-4 2 1 1 6-8 0111 3 3 1 1 81000-1001 2-3 2 2 1 7-8 1010 2 2 2 2 8

TABLE 4 N_(STS) N_(STS) N_(STS) N_(STS) N_(STS) N_(STS) N_(STS) N_(STS)Total Number N_(user) B3 . . . B0 [1] [2] [3] [4] [5] [6] [7] [8]N_(STS) of entries 5 0000-0011 1-4 1 1 1 1 5-8 7 0100-0101 2-3 2 1 1 17-8 0110 2 2 2 1 1 8 6 0000-0010 1-3 1 1 1 1 1 6-8 4 0011 2 2 1 1 1 1 87 0000-0001 1-2 1 1 1 1 1 1 7-8 2 8 0000 1 1 1 1 1 1 1 1 8 1

As shown in Table 3 and/or Table 4, the second bit (e.g., B11-B14) mayinclude information related to the number of spatial streams allocatedto the plurality of user STAs which are allocated based on the MU-MIMOscheme. For example, when three user STAs are allocated to the 106-RUbased on the MU-MIMO scheme as shown in FIG. 9 , N_user is set to “3”.Therefore, values of N_STS[1], N_STS[2], and N_STS[3] may be determinedas shown in Table 3. For example, when a value of the second bit(B11-B14) is “0011”, it may be set to N_STS[1]=4, N_STS[2]=1,N_STS[3]=1. That is, in the example of FIG. 9 , four spatial streams maybe allocated to the user field 1, one spatial stream may be allocated tothe user field 1, and one spatial stream may be allocated to the userfield 3.

As shown in the example of Table 3 and/or Table 4, information (i.e.,the second bit, B11-B14) related to the number of spatial streams forthe user STA may consist of 4 bits. In addition, the information (i.e.,the second bit, B11-B14) on the number of spatial streams for the userSTA may support up to eight spatial streams. In addition, theinformation (i.e., the second bit, B11-B14) on the number of spatialstreams for the user STA may support up to four spatial streams for oneuser STA.

In addition, a third bit (i.e., B15-18) in the user field (i.e., 21bits) may include modulation and coding scheme (MCS) information. TheMCS information may be applied to a data field in a PPDU includingcorresponding SIG-B.

An MCS, MCS information, an MCS index, an MCS field, or the like used inthe present specification may be indicated by an index value. Forexample, the MCS information may be indicated by an index 0 to an index11. The MCS information may include information related to aconstellation modulation type (e.g., BPSK, QPSK, 16-QAM, 64-QAM,256-QAM, 1024-QAM, etc.) and information related to a coding rate (e.g.,1/2, 2/3, 3/4, 5/6e, etc.). Information related to a channel coding type(e.g., LCC or LDPC) may be excluded in the MCS information.

In addition, a fourth bit (i.e., B19) in the user field (i.e., 21 bits)may be a reserved field.

In addition, a fifth bit (i.e., B20) in the user field (i.e., 21 bits)may include information related to a coding type (e.g., BCC or LDPC).That is, the fifth bit (i.e., B20) may include information related to atype (e.g., BCC or LDPC) of channel coding applied to the data field inthe PPDU including the corresponding SIG-B.

The aforementioned example relates to the user field of the first format(the format of the MU-MIMO scheme). An example of the user field of thesecond format (the format of the non-MU-MIMO scheme) is as follows.

A first bit (e.g., B0-B10) in the user field of the second format mayinclude identification information of a user STA. In addition, a secondbit (e.g., B11-B13) in the user field of the second format may includeinformation related to the number of spatial streams applied to acorresponding RU. In addition, a third bit (e.g., B14) in the user fieldof the second format may include information related to whether abeamforming steering matrix is applied. A fourth bit (e.g., B15-B18) inthe user field of the second format may include modulation and codingscheme (MCS) information. In addition, a fifth bit (e.g., B19) in theuser field of the second format may include information related towhether dual carrier modulation (DCM) is applied. In addition, a sixthbit (i.e., B20) in the user field of the second format may includeinformation related to a coding type (e.g., BCC or LDPC).

FIG. 10 illustrates an operation based on UL-MU. As illustrated, atransmitting STA (e.g., an AP) may perform channel access throughcontending (e.g., a backoff operation), and may transmit a trigger frame1030. That is, the transmitting STA may transmit a PPDU including thetrigger frame 1030. Upon receiving the PPDU including the trigger frame,a trigger-based (TB) PPDU is transmitted after a delay corresponding toSIFS.

TB PPDUs 1041 and 1042 may be transmitted at the same time period, andmay be transmitted from a plurality of STAs (e.g., user STAs) havingAIDs indicated in the trigger frame 1030. An ACK frame 1050 for the TBPPDU may be implemented in various forms.

A specific feature of the trigger frame is described with reference toFIG. 11 to FIG. 13 . Even if UL-MU communication is used, an orthogonalfrequency division multiple access (OFDMA) scheme or a MU MIMO schememay be used, and the OFDMA and MU-MIMO schemes may be simultaneouslyused.

FIG. 11 illustrates an example of a trigger frame. The trigger frame ofFIG. 11 allocates a resource for uplink multiple-user (MU) transmission,and may be transmitted, for example, from an AP. The trigger frame maybe configured of a MAC frame, and may be included in a PPDU.

Each field shown in FIG. 11 may be partially omitted, and another fieldmay be added. In addition, a length of each field may be changed to bedifferent from that shown in the figure.

A frame control field 1110 of FIG. 11 may include information related toa MAC protocol version and extra additional control information. Aduration field 1120 may include time information for NAV configurationor information related to an identifier (e.g., AID) of a STA.

In addition, an RA field 1130 may include address information of areceiving STA of a corresponding trigger frame, and may be optionallyomitted. A TA field 1140 may include address information of a STA (e.g.,an AP) which transmits the corresponding trigger frame. A commoninformation field 1150 includes common control information applied tothe receiving STA which receives the corresponding trigger frame. Forexample, a field indicating a length of an L-SIG field of an uplink PPDUtransmitted in response to the corresponding trigger frame orinformation for controlling content of a SIG-A field (i.e., HE-SIG-Afield) of the uplink PPDU transmitted in response to the correspondingtrigger frame may be included. In addition, as common controlinformation, information related to a length of a CP of the uplink PPDUtransmitted in response to the corresponding trigger frame orinformation related to a length of an LTF field may be included.

In addition, per user information fields 1160 #1 to 1160 #Ncorresponding to the number of receiving STAs which receive the triggerframe of FIG. 11 are preferably included. The per user information fieldmay also be called an “allocation field”.

In addition, the trigger frame of FIG. 11 may include a padding field1170 and a frame check sequence field 1180.

Each of the per user information fields 1160 #1 to 1160 #N shown in FIG.11 may include a plurality of subfields.

FIG. 12 illustrates an example of a common information field of atrigger frame. A subfield of FIG. 12 may be partially omitted, and anextra subfield may be added. In addition, a length of each subfieldillustrated may be changed.

A length field 1210 illustrated has the same value as a length field ofan L-SIG field of an uplink PPDU transmitted in response to acorresponding trigger frame, and a length field of the L-SIG field ofthe uplink PPDU indicates a length of the uplink PPDU. As a result, thelength field 1210 of the trigger frame may be used to indicate thelength of the corresponding uplink PPDU.

In addition, a cascade identifier field 1220 indicates whether a cascadeoperation is performed. The cascade operation implies that downlink MUtransmission and uplink MU transmission are performed together in thesame TXOP. That is, it implies that downlink MU transmission isperformed and thereafter uplink MU transmission is performed after apre-set time (e.g., SIFS). During the cascade operation, only onetransmitting device (e.g., AP) may perform downlink communication, and aplurality of transmitting devices (e.g., non-APs) may perform uplinkcommunication.

A CS request field 1230 indicates whether a wireless medium state or aNAV or the like is necessarily considered in a situation where areceiving device which has received a corresponding trigger frametransmits a corresponding uplink PPDU.

An HE-SIG-A information field 1240 may include information forcontrolling content of a SIG-A field (i.e., HE-SIG-A field) of theuplink PPDU in response to the corresponding trigger frame.

A CP and LTF type field 1250 may include information related to a CPlength and LTF length of the uplink PPDU transmitted in response to thecorresponding trigger frame. A trigger type field 1260 may indicate apurpose of using the corresponding trigger frame, for example, typicaltriggering, triggering for beamforming, a request for block ACK/NACK, orthe like.

It may be assumed that the trigger type field 1260 of the trigger framein the present specification indicates a trigger frame of a basic typefor typical triggering. For example, the trigger frame of the basic typemay be referred to as a basic trigger frame.

FIG. 13 illustrates an example of a subfield included in a per userinformation field. A user information field 1300 of FIG. 13 may beunderstood as any one of the per user information fields 1160 #1 to 1160#N mentioned above with reference to FIG. 11 . A subfield included inthe user information field 1300 of FIG. 13 may be partially omitted, andan extra subfield may be added. In addition, a length of each subfieldillustrated may be changed.

A user identifier field 1310 of FIG. 13 indicates an identifier of a STA(i.e., receiving STA) corresponding to per user information. An exampleof the identifier may be the entirety or part of an associationidentifier (AID) value of the receiving STA.

In addition, an RU allocation field 1320 may be included. That is, whenthe receiving STA identified through the user identifier field 1310transmits a TB PPDU in response to the trigger frame, the TB PPDU istransmitted through an RU indicated by the RU allocation field 1320. Inthis case, the RU indicated by the RU allocation field 1320 may be an RUshown in FIG. 5 , FIG. 6 , and FIG. 7 .

The subfield of FIG. 13 may include a coding type field 1330. The codingtype field 1330 may indicate a coding type of the TB PPDU. For example,when BCC coding is applied to the TB PPDU, the coding type field 1330may be set to ‘1’, and when LDPC coding is applied, the coding typefield 1330 may be set to ‘0’.

In addition, the subfield of FIG. 13 may include an MCS field 1340. TheMCS field 1340 may indicate an MCS scheme applied to the TB PPDU. Forexample, when BCC coding is applied to the TB PPDU, the coding typefield 1330 may be set to ‘1’, and when LDPC coding is applied, thecoding type field 1330 may be set to ‘0’.

Hereinafter, a UL OFDMA-based random access (UORA) scheme will bedescribed.

FIG. 14 describes a technical feature of the UORA scheme.

A transmitting STA (e.g., an AP) may allocate six RU resources through atrigger frame as shown in FIG. 14 . Specifically, the AP may allocate a1st RU resource (AID 0, RU 1), a 2nd RU resource (AID 0, RU 2), a 3rd RUresource (AID 0, RU 3), a 4th RU resource (AID 2045, RU 4), a 5th RUresource (AID 2045, RU 5), and a 6th RU resource (AID 3, RU 6).Information related to the AID 0, AID 3, or AID 2045 may be included,for example, in the user identifier field 1310 of FIG. 13 . Informationrelated to the RU 1 to RU 6 may be included, for example, in the RUallocation field 1320 of FIG. 13 . AID=0 may imply a UORA resource foran associated STA, and AID=2045 may imply a UORA resource for anun-associated STA. Accordingly, the 1st to 3rd RU resources of FIG. 14may be used as a UORA resource for the associated STA, the 4th and 5thRU resources of FIG. 14 may be used as a UORA resource for theun-associated STA, and the 6th RU resource of FIG. 14 may be used as atypical resource for UL MU.

In the example of FIG. 14 , an OFDMA random access backoff (OBO) of aSTA1 is decreased to 0, and the STA1 randomly selects the 2nd RUresource (AID 0, RU 2). In addition, since an OBO counter of a STA2/3 isgreater than 0, an uplink resource is not allocated to the STA2/3. Inaddition, regarding a STA4 in FIG. 14 , since an AID (e.g., AID=3) ofthe STA4 is included in a trigger frame, a resource of the RU 6 isallocated without backoff.

Specifically, since the STA1 of FIG. 14 is an associated STA, the totalnumber of eligible RA RUs for the STA1 is 3 (RU 1, RU 2, and RU 3), andthus the STA1 decreases an OBO counter by 3 so that the OBO counterbecomes 0. In addition, since the STA2 of FIG. 14 is an associated STA,the total number of eligible RA RUs for the STA2 is 3 (RU 1, RU 2, andRU 3), and thus the STA2 decreases the OBO counter by 3 but the OBOcounter is greater than 0. In addition, since the STA3 of FIG. 14 is anun-associated STA, the total number of eligible RA RUs for the STA3 is 2(RU 4, RU 5), and thus the STA3 decreases the OBO counter by 2 but theOB 0 counter is greater than 0.

FIG. 15 illustrates an example of a channel used/supported/definedwithin a 2.4 GHz band.

The 2.4 GHz band may be called in other terms such as a first band. Inaddition, the 2.4 GHz band may imply a frequency domain in whichchannels of which a center frequency is close to 2.4 GHz (e.g., channelsof which a center frequency is located within 2.4 to 2.5 GHz) areused/supported/defined.

A plurality of 20 MHz channels may be included in the 2.4 GHz band. 20MHz within the 2.4 GHz may have a plurality of channel indices (e.g., anindex 1 to an index 14). For example, a center frequency of a 20 MHzchannel to which a channel index 1 is allocated may be 2.412 GHz, acenter frequency of a 20 MHz channel to which a channel index 2 isallocated may be 2.417 GHz, and a center frequency of a 20 MHz channelto which a channel index N is allocated may be (2.407+0.005*N) GHz. Thechannel index may be called in various terms such as a channel number orthe like. Specific numerical values of the channel index and centerfrequency may be changed.

FIG. 15 exemplifies 4 channels within a 2.4 GHz band. Each of 1st to 4thfrequency domains 1510 to 1540 shown herein may include one channel. Forexample, the 1st frequency domain 1510 may include a channel 1 (a 20 MHzchannel having an index 1). In this case, a center frequency of thechannel 1 may be set to 2412 MHz. The 2nd frequency domain 1520 mayinclude a channel 6. In this case, a center frequency of the channel 6may be set to 2437 MHz. The 3rd frequency domain 1530 may include achannel 11. In this case, a center frequency of the channel 11 may beset to 2462 MHz. The 4th frequency domain 1540 may include a channel 14.In this case, a center frequency of the channel 14 may be set to 2484MHz.

FIG. 16 illustrates an example of a channel used/supported/definedwithin a 5 GHz band.

The 5 GHz band may be called in other terms such as a second band or thelike. The 5 GHz band may imply a frequency domain in which channels ofwhich a center frequency is greater than or equal to 5 GHz and less than6 GHz (or less than 5.9 GHz) are used/supported/defined. Alternatively,the 5 GHz band may include a plurality of channels between 4.5 GHz and5.5 GHz. A specific numerical value shown in FIG. 16 may be changed.

A plurality of channels within the 5 GHz band include an unlicensednational information infrastructure (UNII)-1, a UNII-2, a UNII-3, and anISM. The INII-1 may be called UNII Low. The UNII-2 may include afrequency domain called UNII Mid and UNII-2Extended. The UNII-3 may becalled UNII-Upper.

A plurality of channels may be configured within the 5 GHz band, and abandwidth of each channel may be variously set to, for example, 20 MHz,40 MHz, 80 MHz, 160 MHz, or the like. For example, 5170 MHz to 5330 MHzfrequency domains/ranges within the UNII-1 and UNII-2 may be dividedinto eight 20 MHz channels. The 5170 MHz to 5330 MHz frequencydomains/ranges may be divided into four channels through a 40 MHzfrequency domain. The 5170 MHz to 5330 MHz frequency domains/ranges maybe divided into two channels through an 80 MHz frequency domain.Alternatively, the 5170 MHz to 5330 MHz frequency domains/ranges may bedivided into one channel through a 160 MHz frequency domain.

FIG. 17 illustrates an example of a channel used/supported/definedwithin a 6 GHz band.

The 6 GHz band may be called in other terms such as a third band or thelike. The 6 GHz band may imply a frequency domain in which channels ofwhich a center frequency is greater than or equal to 5.9 GHz areused/supported/defined. A specific numerical value shown in FIG. 17 maybe changed.

For example, the 20 MHz channel of FIG. 17 may be defined starting from5.940 GHz. Specifically, among 20 MHz channels of FIG. 17 , the leftmostchannel may have an index 1 (or a channel index, a channel number,etc.), and 5.945 GHz may be assigned as a center frequency. That is, acenter frequency of a channel of an index N may be determined as(5.940+0.005*N) GHz.

Accordingly, an index (or channel number) of the 2 MHz channel of FIG.17 may be 1, 5, 9, 13, 17, 21, 25, 29, 33, 37, 41, 45, 49, 53, 57, 61,65, 69, 73, 77, 81, 85, 89, 93, 97, 101, 105, 109, 113, 117, 121, 125,129, 133, 137, 141, 145, 149, 153, 157, 161, 165, 169, 173, 177, 181,185, 189, 193, 197, 201, 205, 209, 213, 217, 221, 225, 229, 233. Inaddition, according to the aforementioned (5.940+0.005*N)GHz rule, anindex of the 40 MHz channel of FIG. 17 may be 3, 11, 19, 27, 35, 43, 51,59, 67, 75, 83, 91, 99, 107, 115, 123, 131, 139, 147, 155, 163, 171,179, 187, 195, 203, 211, 219, 227.

Although 20, 40, 80, and 160 MHz channels are illustrated in the exampleof FIG. 17 , a 240 MHz channel or a 320 MHz channel may be additionallyadded.

Hereinafter, a PPDU transmitted/received in a STA of the presentspecification will be described.

FIG. 18 illustrates an example of a PPDU used in the presentspecification.

The PPDU of FIG. 18 may be called in various terms such as an EHT PPDU,a TX PPDU, an RX PPDU, a first type or N-th type PPDU, or the like. Forexample, in the present specification, the PPDU or the EHT PPDU may becalled in various terms such as a TX PPDU, a RX PPDU, a first type orN-th type PPDU, or the like. In addition, the EHT PPDU may be used in anEHT system and/or a new WLAN system enhanced from the EHT system.

The PPDU of FIG. 18 may represent some or all of the PPDU types used inthe EHT system. For example, the example of FIG. 18 may be used for botha single-user (SU) mode and a multi-user (MU) mode, or may be used onlyfor the SU mode, or may be used only for the MU mode. For example, atrigger-based (TB) PPDU on the EHT system may be separately defined orconfigured based on the example of FIG. 18 . The trigger frame describedthrough at least one of FIGS. 10 to 14 and the UL-MU operation initiatedby the trigger frame (for example, the transmission operation of the TBPPDU) may be directly applied to the EHT system.

In FIG. 18 , an L-STF to an EHT-LTF may be called a preamble or aphysical preamble, and may begenerated/transmitted/received/obtained/decoded in a physical layer.

A subcarrier spacing of the L-STF, L-LTF, L-SIG, RL-SIG, U-SIG, andEHT-SIG fields of FIG. 18 may be determined as 312.5 kHz, and asubcarrier spacing of the EHT-STF, EHT-LTF, and Data fields may bedetermined as 78.125 kHz. That is, a tone index (or subcarrier index) ofthe L-STF, L-LTF, L-SIG, RL-SIG, U-SIG, and EHT-SIG fields may beexpressed in unit of 312.5 kHz, and a tone index (or subcarrier index)of the EHT-STF, EHT-LTF, and Data fields may be expressed in unit of78.125 kHz.

In the PPDU of FIG. 18 , the L-LTE and the L-STF may be the same asthose in the conventional fields.

The L-SIG field of FIG. 18 may include, for example, bit information of24 bits. For example, the 24-bit information may include a rate field of4 bits, a reserved bit of 1 bit, a length field of 12 bits, a parity bitof 1 bit, and a tail bit of 6 bits. For example, the length field of 12bits may include information related to a length or time duration of aPPDU. For example, the length field of 12 bits may be determined basedon a type of the PPDU. For example, when the PPDU is a non-HT, HT, VHTPPDU or an EHT PPDU, a value of the length field may be determined as amultiple of 3. For example, when the PPDU is an HE PPDU, the value ofthe length field may be determined as “a multiple of 3”+1 or “a multipleof 3”+2. In other words, for the non-HT, HT, VHT PPDI or the EHT PPDU,the value of the length field may be determined as a multiple of 3, andfor the HE PPDU, the value of the length field may be determined as “amultiple of 3”+1 or “a multiple of 3”+2.

For example, the transmitting STA may apply BCC encoding based on a 1/2coding rate to the 24-bit information of the L-SIG field. Thereafter,the transmitting STA may obtain a BCC coding bit of 48 bits. BPSKmodulation may be applied to the 48-bit coding bit, thereby generating48 BPSK symbols. The transmitting STA may map the 48 BPSK symbols topositions except for a pilot subcarrier{subcarrier index −21, −7, +7,+21} and a DC subcarrier{subcarrier index 0}. As a result, the 48 BPSKsymbols may be mapped to subcarrier indices −26 to −22, −20 to −8, −6 to−1, +1 to +6, +8 to +20, and +22 to +26. The transmitting STA mayadditionally map a signal of {−1, −1, −1, 1} to a subcarrier index{−28,−27, +27, +28}. The aforementioned signal may be used for channelestimation on a frequency domain corresponding to {−28, −27, +27, +28}.

The transmitting STA may generate an RL-SIG generated in the same manneras the L-SIG. BPSK modulation may be applied to the RL-SIG. Thereceiving STA may know that the RX PPDU is the HE PPDU or the EHT PPDU,based on the presence of the RL-SIG.

A universal SIG (U-SIG) may be inserted after the RL-SIG of FIG. 18 .The U-SIB may be called in various terms such as a first SIG field, afirst SIG, a first type SIG, a control signal, a control signal field, afirst (type) control signal, or the like.

The U-SIG may include information of N bits, and may include informationfor identifying a type of the EHT PPDU. For example, the U-SIG may beconfigured based on two symbols (e.g., two contiguous OFDM symbols).Each symbol (e.g., OFDM symbol) for the U-SIG may have a duration of 4us. Each symbol of the U-SIG may be used to transmit the 26-bitinformation. For example, each symbol of the U-SIG may betransmitted/received based on 52 data tomes and 4 pilot tones.

Through the U-SIG (or U-SIG field), for example, A-bit information(e.g., 52 un-coded bits) may be transmitted. A first symbol of the U-SIGmay transmit first X-bit information (e.g., 26 un-coded bits) of theA-bit information, and a second symbol of the U-SIB may transmit theremaining Y-bit information (e.g. 26 un-coded bits) of the A-bitinformation. For example, the transmitting STA may obtain 26 un-codedbits included in each U-SIG symbol. The transmitting STA may performconvolutional encoding (i.e., BCC encoding) based on a rate of R=1/2 togenerate 52-coded bits, and may perform interleaving on the 52-codedbits. The transmitting STA may perform BPSK modulation on theinterleaved 52-coded bits to generate 52 BPSK symbols to be allocated toeach U-SIG symbol. One U-SIG symbol may be transmitted based on 65 tones(subcarriers) from a subcarrier index −28 to a subcarrier index +28,except for a DC index 0. The 52 BPSK symbols generated by thetransmitting STA may be transmitted based on the remaining tones(subcarriers) except for pilot tones, i.e., tones −21, −7, +7, +21.

For example, the A-bit information (e.g., 52 un-coded bits) generated bythe U-SIG may include a CRC field (e.g., a field having a length of 4bits) and a tail field (e.g., a field having a length of 6 bits). TheCRC field and the tail field may be transmitted through the secondsymbol of the U-SIG. The CRC field may be generated based on 26 bitsallocated to the first symbol of the U-SIG and the remaining 16 bitsexcept for the CRC/tail fields in the second symbol, and may begenerated based on the conventional CRC calculation algorithm. Inaddition, the tail field may be used to terminate trellis of aconvolutional decoder, and may be set to, for example, “000000”.

The A-bit information (e.g., 52 un-coded bits) transmitted by the U-SIG(or U-SIG field) may be divided into version-independent bits andversion-dependent bits. For example, the version-independent bits mayhave a fixed or variable size. For example, the version-independent bitsmay be allocated only to the first symbol of the U-SIG, or theversion-independent bits may be allocated to both of the first andsecond symbols of the U-SIG. For example, the version-independent bitsand the version-dependent bits may be called in various terms such as afirst control bit, a second control bit, or the like.

For example, the version-independent bits of the U-SIG may include a PHYversion identifier of 3 bits. For example, the PHY version identifier of3 bits may include information related to a PHY version of a TX/RX PPDU.For example, a first value of the PHY version identifier of 3 bits mayindicate that the TX/RX PPDU is an EHT PPDU. In other words, when thetransmitting STA transmits the EHT PPDU, the PHY version identifier of 3bits may be set to a first value. In other words, the receiving STA maydetermine that the RX PPDU is the EHT PPDU, based on the PHY versionidentifier having the first value.

For example, the version-independent bits of the U-SIG may include aUL/DL flag field of 1 bit. A first value of the UL/DL flag field of 1bit relates to UL communication, and a second value of the UL/DL flagfield relates to DL communication.

For example, the version-independent bits of the U-SIG may includeinformation related to a TXOP length and information related to a BSScolor ID.

For example, when the EHT PPDU is divided into various types (e.g.,various types such as an EHT PPDU related to an SU mode, an EHT PPDUrelated to a MU mode, an EHT PPDU related to a TB mode, an EHT PPDUrelated to extended range transmission, or the like), informationrelated to the type of the EHT PPDU may be included in theversion-dependent bits of the U-SIG.

For example, the U-SIG may include: 1) a bandwidth field includinginformation related to a bandwidth; 2) a field including informationrelated to an MCS scheme applied to EHT-SIG; 3) an indication fieldincluding information regarding whether a dual subcarrier modulation(DCM) scheme is applied to EHT-SIG; 4) a field including informationrelated to the number of symbol used for EHT-SIG; 5) a field includinginformation regarding whether the EHT-SIG is generated across a fullband; 6) a field including information related to a type of EHT-LTF/STF;and 7) information related to a field indicating an EHT-LTF length and aCP length.

Preamble puncturing may be applied to the PPDU of FIG. 18 . The preamblepuncturing implies that puncturing is applied to part (e.g., a secondary20 MHz band) of the full band. For example, when an 80 MHz PPDU istransmitted, an STA may apply puncturing to the secondary 20 MHz bandout of the 80 MHz band, and may transmit a PPDU only through a primary20 MHz band and a secondary 40 MHz band.

For example, a pattern of the preamble puncturing may be configured inadvance. For example, when a first puncturing pattern is applied,puncturing may be applied only to the secondary 20 MHz band within the80 MHz band. For example, when a second puncturing pattern is applied,puncturing may be applied to only any one of two secondary 20 MHz bandsincluded in the secondary 40 MHz band within the 80 MHz band. Forexample, when a third puncturing pattern is applied, puncturing may beapplied to only the secondary 20 MHz band included in the primary 80 MHzband within the 160 MHz band (or 80+80 MHz band). For example, when afourth puncturing is applied, puncturing may be applied to at least one20 MHz channel not belonging to a primary 40 MHz band in the presence ofthe primary 40 MHz band included in the 80 MHz band within the 160 MHzband (or 80+80 MHz band).

Information related to the preamble puncturing applied to the PPDU maybe included in U-SIG and/or EHT-SIG. For example, a first field of theU-SIG may include information related to a contiguous bandwidth, andsecond field of the U-SIG may include information related to thepreamble puncturing applied to the PPDU.

For example, the U-SIG and the EHT-SIG may include the informationrelated to the preamble puncturing, based on the following method. Whena bandwidth of the PPDU exceeds 80 MHz, the U-SIG may be configuredindividually in unit of 80 MHz. For example, when the bandwidth of thePPDU is 160 MHz, the PPDU may include a first U-SIG for a first 80 MHzband and a second U-SIG for a second 80 MHz band. In this case, a firstfield of the first U-SIG may include information related to a 160 MHzbandwidth, and a second field of the first U-SIG may include informationrelated to a preamble puncturing (i.e., information related to apreamble puncturing pattern) applied to the first 80 MHz band. Inaddition, a first field of the second U-SIG may include informationrelated to a 160 MHz bandwidth, and a second field of the second U-SIGmay include information related to a preamble puncturing (i.e.,information related to a preamble puncturing pattern) applied to thesecond 80 MHz band. Meanwhile, an EHT-SIG contiguous to the first U-SIGmay include information related to a preamble puncturing applied to thesecond 80 MHz band (i.e., information related to a preamble puncturingpattern), and an EHT-SIG contiguous to the second U-SIG may includeinformation related to a preamble puncturing (i.e., information relatedto a preamble puncturing pattern) applied to the first 80 MHz band.

Additionally or alternatively, the U-SIG and the EHT-SIG may include theinformation related to the preamble puncturing, based on the followingmethod. The U-SIG may include information related to a preamblepuncturing (i.e., information related to a preamble puncturing pattern)for all bands. That is, the EHT-SIG may not include the informationrelated to the preamble puncturing, and only the U-SIG may include theinformation related to the preamble puncturing (i.e., the informationrelated to the preamble puncturing pattern).

The U-SIG may be configured in unit of 20 MHz. For example, when an 80MHz PPDU is configured, the U-SIG may be duplicated. That is, fouridentical U-SIGs may be included in the 80 MHz PPDU. PPDUs exceeding an80 MHz bandwidth may include different U-SIGs.

The EHT-SIG of FIG. 18 may include the technical features of theHE-SIG-B shown in the examples of FIGS. 8 to 9 . The EHT-SIG may bereferred to by various names such as a second SIG field, a second SIG, asecond type SIG, a control signal, a control signal field, and a second(type) control signal.

The EHT-SIG may include N-bit information (for example, 1-bitinformation) regarding whether the EHT-PPDU supports the SU mode or theMU mode.

The EHT-SIG may be configured based on various MCS scheme. As describedabove, information related to the MCS scheme applied to the EHT-SIG maybe included in the U-SIG. The EHT-SIG may be configured based on the DCMscheme. For example, among the N data tones (for example, 52 data tones)allocated for the EHT-SIG, a first modulation scheme may be applied to acontiguous half tone, and a second modulation scheme may be applied tothe remaining contiguous half tones. That is, the transmitting STA maymodulate specific control information to the first symbol based on thefirst modulation scheme and allocate it to contiguous half tones, andmay modulate the same control information to the second symbol based onthe second modulation scheme and allocate it to the remaining contiguoushalf tones. As described above, information (for example, 1-bit field)related to whether the DCM scheme is applied to the EHT-SIG may beincluded in the U-SIG. The EHT-STF of FIG. 18 may be used to improveautomatic gain control estimation in a multiple input multiple output(MIMO) environment or an OFDMA environment. The EHT-LTF of FIG. 18 maybe used to estimate a channel in a MIMO environment or an OFDMAenvironment. An HE-STF of FIG. 18 may be used for improving automaticgain control estimation in a multiple input multiple output (MIMO)environment or an OFDMA environment. An HE-LTF of FIG. 18 may be usedfor estimating a channel in the MIMO environment or the OFDMAenvironment.

The EHT-STF of FIG. 18 may be set in various types. For example, a firsttype of STF (e.g., lx STF) may be generated based on a first type STFsequence in which a non-zero coefficient is arranged with an interval of16 subcarriers. An STF signal generated based on the first type STFsequence may have a period of 0.8 μs, and a periodicity signal of 0.8 μsmay be repeated 5 times to become a first type STF having a length of 4μs. For example, a second type of STF (e.g., 2×STF) may be generatedbased on a second type STF sequence in which a non-zero coefficient isarranged with an interval of 8 subcarriers. An STF signal generatedbased on the second type STF sequence may have a period of 1.6p, and aperiodicity signal of 1.6 μs may be repeated 5 times to become a secondtype STF having a length of 8 μs. Hereinafter, an example of a sequencefor configuring an EHT-STF (i.e., an EHT-STF sequence) is proposed. Thefollowing sequence may be modified in various ways.

The EHT-STF may be configured based on the following sequence M.M={−1,−1,−1,1,1,1,−1,1,1,1,−1,1,1,−1,1}  <Equation 1>

The EHT-STF for the 20 MHz PPDU may be configured based on the followingequation. The following example may be a first type (i.e., lx STF)sequence. For example, the first type sequence may be included in not atrigger-based (TB) PPDU but an EHT-PPDU. In the following equation,(a:b:c) may imply a duration defined as b tone intervals (i.e., asubcarrier interval) from a tone index (i.e., subcarrier index) ‘a’ to atone index ‘c’. For example, the equation 2 below may represent asequence defined as 16 tone intervals from a tone index −112 to a toneindex 112. Since a subcarrier spacing of 78.125 kHz is applied to theEHT-STR, the 16 tone intervals may imply that an EHT-STF coefficient (orelement) is arranged with an interval of 78.125*16=1250 kHz. Inaddition, * implies multiplication, and sqrt( ) implies a square root.In addition, j implies an imaginary number.EHT-STF(−112:16:112)={M}*(1+j)/sqrt(2)EHT-STF(0)=0  <Equation 2>

The EHT-STF for the 40 MHz PPDU may be configured based on the followingequation. The following example may be the first type (i.e., lx STF)sequence.EHT-STF(−240:16:240)={M,0,−M}*(1+j)/sqrt(2)  <Equation 3>

The EHT-STF for the 80 MHz PPDU may be configured based on the followingequation. The following example may be the first type (i.e., lx STF)sequence.EHT-STF(−496:16:496)={M,1,−M,0,−M,1,−M}*(1+j)/sqrt(2)  <Equation 4>

The EHT-STF for the 160 MHz PPDU may be configured based on thefollowing equation. The following example may be the first type (i.e.,lx STF) sequence.EHT-STF(−1008:16:1008)={M,1,−M,0,−M,1,−M,0,−M,−1,M,0,−M,1,−M}*(1+j)/sqrt(2)  <Equation5>

In the EHT-STF for the 80+80 MHz PPDU, a sequence for lower 80 MHz maybe identical to Equation 4. In the EHT-STF for the 80+80 MHz PPDU, asequence for upper 80 MHz may be configured based on the followingequation.EHT-STF(−496:16:496)={−M,−1,M,0,−M,1,−M}*(1+j)/sqrt(2)  <Equation 6>

Equation 7 to Equation 11 below relate to an example of a second type(i.e., 2×STF) sequence.EHT-STF(−120:8:120)={M,0,−M}*(1+j)/sqrt(2)  <Equation 7>

The EHT-STF for the 40 MHz PPDU may be configured based on the followingequation.EHT-STF(−248:8:248)={M,−1,−M,0,M,−1,M}*(1+j)/sqrt(2)EHT-STF(−248)=0EHT-STF(248)=0  <Equation 8>

The EHT-STF for the 80 MHz PPDU may be configured based on the followingequation.EHT-STF(−504:8:504)={M,−1,M,−1,−M,−1,M,0,−M,1,M,1,−M,1,−M}*(1+j)/sqrt(2)  <Equation9>

The EHT-STF for the 160 MHz PPDU may be configured based on thefollowing equation.EHT-STF(−1016:16:1016)={M,−1,M,−1,−M,−1,M,0,−M,1,M,1,−M,1,−M,0,−M,1,−M,1,M,1,−M,0,−M,1,M,1,−M,1,−M}*(1+j)/sqrt(2)EHT-STF(−8)=0,EHT-STF(8)=0,EHT-STF(−1016)=0,EHT-STF(1016)=0  <Equation 10>

In the EHT-STF for the 80+80 MHz PPDU, a sequence for lower 80 MHz maybe identical to Equation 9. In the EHT-STF for the 80+80 MHz PPDU, asequence for upper 80 MHz may be configured based on the followingequation.EHT-STF(−504:8:504)={−M,1,−M,1,M,1,−M,0,−M,1,M,1,−M,1,−M}*(1+j)/sqrt(2)EHT-STF(−504)=0,EHT-STF(504)=0  <Equation 11>

The EHT-LTF may have first, second, and third types (i.e., 1×, 2×,4×LTF). For example, the first/second/third type LTF may be generatedbased on an LTF sequence in which a non-zero coefficient is arrangedwith an interval of 4/2/1 subcarriers. The first/second/third type LTFmay have a time length of 3.2/6.4/12.8p. In addition, a GI (e.g.,0.8/1/6/3.2 μs) having various lengths may be applied to thefirst/second/third type LTF.

Information related to a type of STF and/or LTF (information related toa GI applied to LTF is also included) may be included in a SIG-A fieldand/or SIG-B field or the like of FIG. 18 .

A PPDU (e.g., EHT-PPDU) of FIG. 18 may be configured based on theexample of FIG. 5 and FIG. 6 .

For example, an EHT PPDU transmitted on a 20 MHz band, i.e., a 20 MHzEHT PPDU, may be configured based on the RU of FIG. 5 . That is, alocation of an RU of EHT-STF, EHT-LTF, and data fields included in theEHT PPDU may be determined as shown in FIG. 5 .

An EHT PPDU transmitted on a 40 MHz band, i.e., a 40 MHz EHT PPDU, maybe configured based on the RU of FIG. 6 . That is, a location of an RUof EHT-STF, EHT-LTF, and data fields included in the EHT PPDU may bedetermined as shown in FIG. 6 .

Since the RU location of FIG. 6 corresponds to 40 MHz, a tone-plan for80 MHz may be determined when the pattern of FIG. 6 is repeated twice.That is, an 80 MHz EHT PPDU may be transmitted based on a new tone-planin which not the RU of FIG. 7 but the RU of FIG. 6 is repeated twice.

When the pattern of FIG. 6 is repeated twice, 23 tones (i.e., 11 guardtones+12 guard tones) may be configured in a DC region. That is, atone-plan for an 80 MHz EHT PPDU allocated based on OFDMA may have 23 DCtones. Unlike this, an 80 MHz EHT PPDU allocated based on non-OFDMA(i.e., a non-OFDMA full bandwidth 80 MHz PPDU) may be configured basedon a 996-RU, and may include 5 DC tones, 12 left guard tones, and 11right guard tones.

A tone-plan for 160/240/320 MHz may be configured in such a manner thatthe pattern of FIG. 6 is repeated several times.

The PPDU of FIG. 18 may be determined (or identified) as an EHT PPDUbased on the following method.

A receiving STA may determine a type of an RX PPDU as the EHT PPDU,based on the following aspect. For example, the RX PPDU may bedetermined as the EHT PPDU: 1) when a first symbol after an L-LTF signalof the RX PPDU is a BPSK symbol; 2) when RL-SIG in which the L-SIG ofthe RX PPDU is repeated is detected; and 3) when a result of applying“modulo 3” to a value of a length field of the L-SIG of the RX PPDU isdetected as “0”. When the RX PPDU is determined as the EHT PPDU, thereceiving STA may detect a type of the EHT PPDU (e.g., anSU/MU/Trigger-based/Extended Range type), based on bit informationincluded in a symbol after the RL-SIG of FIG. 18 . In other words, thereceiving STA may determine the RX PPDU as the EHT PPDU, based on: 1) afirst symbol after an L-LTF signal, which is a BPSK symbol; 2) RL-SIGcontiguous to the L-SIG field and identical to L-SIG; 3) L-SIG includinga length field in which a result of applying “modulo 3” is set to “0”;and 4) a 3-bit PHY version identifier of the aforementioned U-SIG (e.g.,a PHY version identifier having a first value).

For example, the receiving STA may determine the type of the RX PPDU asthe EHT PPDU, based on the following aspect. For example, the RX PPDUmay be determined as the HE PPDU: 1) when a first symbol after an L-LTFsignal is a BPSK symbol; 2) when RL-SIG in which the L-SIG is repeatedis detected; and 3) when a result of applying “modulo 3” to a value of alength field of the L-SIG is detected as “1” or “2”.

For example, the receiving STA may determine the type of the RX PPDU asa non-HT, HT, and VHT PPDU, based on the following aspect. For example,the RX PPDU may be determined as the non-HT, HT, and VHT PPDU: 1) when afirst symbol after an L-LTF signal is a BPSK symbol; and 2) when RL-SIGin which L-SIG is repeated is not detected. In addition, even if thereceiving STA detects that the RL-SIG is repeated, when a result ofapplying “modulo 3” to the length value of the L-SIG is detected as “0”,the RX PPDU may be determined as the non-HT, HT, and VHT PPDU.

In the following example, a signal represented as a (TX/RX/UL/DL)signal, a (TX/RX/UL/DL) frame, a (TX/RX/UL/DL) packet, a (TX/RX/UL/DL)data unit, (TX/RX/UL/DL) data, or the like may be a signaltransmitted/received based on the PPDU of FIG. 18 . The PPDU of FIG. 18may be used to transmit/receive frames of various types. For example,the PPDU of FIG. 18 may be used for a control frame. An example of thecontrol frame may include a request to send (RTS), a clear to send(CTS), a power save-poll (PS-poll), BlockACKReq, BlockAck, a null datapacket (NDP) announcement, and a trigger frame. For example, the PPDU ofFIG. 18 may be used for a management frame. An example of the managementframe may include a beacon frame, a (re-)association request frame, a(re-)association response frame, a probe request frame, and a proberesponse frame. For example, the PPDU of FIG. 18 may be used for a dataframe. For example, the PPDU of FIG. 18 may be used to simultaneouslytransmit at least two or more of the control frame, the managementframe, and the data frame.

FIG. 19 illustrates an example of a modified transmission device and/orreceiving device of the present specification.

Each device/STA of the sub-figure (a)/(b) of FIG. 1 may be modified asshown in FIG. 19 . A transceiver 630 of FIG. 19 may be identical to thetransceivers 113 and 123 of FIG. 1 . The transceiver 630 of FIG. 19 mayinclude a receiver and a transmitter.

A processor 610 of FIG. 19 may be identical to the processors 111 and121 of FIG. 1 . Alternatively, the processor 610 of FIG. 19 may beidentical to the processing chips 114 and 124 of FIG. 1 .

A memory 620 of FIG. 19 may be identical to the memories 112 and 122 ofFIG. 1 . Alternatively, the memory 620 of FIG. 19 may be a separateexternal memory different from the memories 112 and 122 of FIG. 1 .

Referring to FIG. 19 , a power management module 611 manages power forthe processor 610 and/or the transceiver 630. A battery 612 suppliespower to the power management module 611. A display 613 outputs a resultprocessed by the processor 610. A keypad 614 receives inputs to be usedby the processor 610. The keypad 614 may be displayed on the display613. A SIM card 615 may be an integrated circuit which is used tosecurely store an international mobile subscriber identity (IMSI) andits related key, which are used to identify and authenticate subscriberson mobile telephony devices such as mobile phones and computers.

Referring to FIG. 19 , a speaker 640 may output a result related to asound processed by the processor 610. A microphone 641 may receive aninput related to a sound to be used by the processor 610.

In the following specification, an EHT standard or a PPDU in compliancewith the EHT standard may be described.

In order to provide a higher data rate than the 802.11ax standard, theEHT standard may be proposed. The EHT standard may support a widebandwidth (e.g., a bandwidth of 320 MHz or more), 16 streams, and/ormulti-link (or multi-band) operation. Accordingly, to support atransmission method based on the EHT standard, a new frame format may beused. When transmitting a signal through the 2.4/5/6 GHz band using thenew frame format, conventional Wi-Fi receivers/STAs (e.g., receivers of802.11n/ac/ax standards) as well as receivers supported by the EHTstandard may also receive the EHT signal transmitted through the 2.4/5/6GHz band.

Hereinafter, while supporting backward compatibility with theconventional Wi-Fi (e.g., 802.11n/ac/ax standard), technical featuresfor an EHT PPDU (e.g., a common control field) indicating a PPDU (orpacket) of the 802.11be standard may be proposed.

The preamble of the PPDU based on the EHT standard may be set in variousways. Hereinafter, an embodiment in which a preamble of a PPDU based onthe EHT standard is configured may be described. Hereinafter, a PPDUbased on the EHT standard may be described as an EHT PPDU. However, theEHT PPDU is not limited to the EHT standard. The EHT PPDU may beconfigured based new standard that is an improvement/evolution/extensionof the 802.11be standard as well as the 802.11be standard (i.e., the EHTstandard).

According to an embodiment, the EHT PPDU may be configured to include anL-part and an EHT-part based on the frame format of the 802.11axstandard. An example of the configuration of the EHT PPDU may bedescribed in FIG. 20 .

FIG. 20 shows an example of an EHT PPDU.

Referring to FIG. 20 , the EHT PPDU 2000 may be configured by using aframe of a PPDU defined based on the 802.11ax standard. The EHT PPDU2000 may include an L-part 2010 and an EHT-part 2020.

The EHT PPDU 2000 may be configured in a structure in which the L-part2010 is first transmitted before the EHT-part 2020 for coexistence withthe legacy STA (e.g., STAs according to the 802.11n/ac/ax standard).

According to an embodiment, same as the frame format of the 802.11axstandard, the EHT part 2020 may include the RL-SIG, EHT control field(e.g., U-SIG (not shown) and/or EHT-SIG), EHT-STF, EHT-LTF, and EHT-datafield

According to an embodiment, the RL-SIG may be omitted/skipped in the EHTpart 2020. That is, the EHT part 2020 may include the EHT control field(e.g., U-SIG (not shown) and/or EHT-SIG), EHT-STF, EHT-LTF, and EHT-datafield.

According to an embodiment, when a signal is transmitted through the EHTPPDU 2000 shown in FIG. 20 , in order to reduce the packet falsedetection for a third party device (e.g., STAs of 802.11n/11ac/11axstandard) and to support the packet indication for the PPDU, then EHTcontrol field (or EHT signal field) may be variouslyproposed/configured.

For example, the EHT signal field may be configured as three separatefields. As an example, the EHT signal field may include EHT-SIG1,EHT-SIG2 and/or EHT-SIG3. In other words, the EHT signal field may becomposed of the EHT-SIG1, EHT-SIG2, and EHT-SIG3.

For example, among the EHT signal fields, the EHT-SIG1 and/or EHT-SIG2may include common control information and/or information related to afuture generation Wi-Fi standard. For example, the EHT-SIG3 may includeuser specific information.

For example, the EHT-SIG3 may be included in the EHT-SU/MU PPDU whentransmitting an EHT PPDU (or EHT signal) for multiple users.Alternatively, the EHT-SIG3 may be included in the EHT-SU/MU PPDU totransmit the EHT PPDU (or EHT signal) to which preamble puncturing isapplied.

According to an embodiment, the above-described SIG fields (e.g., theEHT-SIG1, EHT-SIG2, and EHT-SIG3) may be separately/individuallyencoded, and thus each of the SIG fields may include CRC bit(s) and tailbit(s).

For example, the EHT-SIG1 and EHT-SIG2 may be configured by applyingMCS0 (i.e., BCC ½ and BPSK). For another example, the EHT-SIG3 may beconfigured by applying various MCSs. The indication information relatedto the MCS of the EHT-SIG3 may be transmitted through the EHT-SIG1 orEHT-SIG2. In other words, the EHT-SIG1 or EHT-SIG2 may includeinformation related to the MCS of the EHT-SIG3.

Unlike the above-described embodiment, most common information andinformation related to power saving may be transmitted through EHT-SIG1.Accordingly, the EHT-SIG2 may be transmitted by applying various MCSs,not robust MCS (e.g., MCS0). Indication information related to the MCSof the EHT-SIG2 may be transmitted through the EHT-SIG1. In other words,the EHT-SIG1 may include information related to the MCS of the EHT-SIG2.

FIG. 21 shows an example of an EHT signal field.

Referring to FIG. 21 , the EHT signal field may include EHT-SIG1 2110and EHT-SIG2 2120. Although not shown, the EHT signal field may furtherinclude EHT-SIG3. For example, the EHT-SIG1 2110 and the EHT-SIG2 2120may each consist of 1 or 2 symbols. As an example, the EHT-SIG1 2110 mayconsist of 2 symbols. In addition, the EHT-SIG2 2120 may consist of 1 or2 symbols.

Hereinafter, information included in the EHT-SIG1, EHT-SIG2, andEHT-SIG3 included in EHT-SIG may be described. The EHT-SIG1, EHT-SIG2,and EHT-SIG3 included in the above-described EHT-SIG are exemplary andmay be named variously. For example, the EHT-SIG1, EHT-SIG2 and EHT-SIG3may be named Pre-SIG (or U-SIG), EHT-SIGA and EHT-SIGB, respectively.

1. EHT-SIG1 Configuration

A. According to an embodiment, the EHT-SIG1 may be positioned after theRL-SIG. The EHT-SIG1 may include information related to the nextversion, future version, or future Wi-Fi.

B. According to an embodiment, the EHT-SIG1 may include various types ofinformation. Hereinafter, examples of the various information that maybe included in the EHT-SIG1 may be described. According to anembodiment, the EHT-SIG1 may include information required to interpretthe EHT PPDU. According to an embodiment, the EHT-SIG1 may include atleast some or all of information fields included in HE-SIGA of 802.11ax.

B-i) Information Related to Packet Indication (or PHY Identifier)

Information related to the packet indication (or PHY identifier) may beconfigured as 3-bit information. Information related to the Packetindication (or PHY identifier) may be used for an indication(indication) regarding the 802.11be standard (i.e., EHT standard) and afuture version. In other words, the information related to the Packetindication (or PHY identifier) may include information related to the802.11be standard (i.e., EHT standard) and a future version.

B-ii) Information Related to Frame Format Indication

Information related to the frame format indication may has a length of 2or 3 bits. Information related to the frame format indication may beused for an indication of the PPDU format. In other words, theinformation related to the frame format indication may includeinformation related to the format of the PPDU.

B-ii)-1. Unlike the 802.11ax standard, a value of the length field ofthe EHT PPDU (e.g., L-SIG of the EHT PPDU) may be divided by three. Inother words, when a value of the length field of the EHT PPDU is dividedby 3, the remainder may be zero ‘0’. In other words, the result of the‘modulo 3 (mod 3)’ operation to a value of the length field of the EHTPPDU may be set to zero (0). Therefore, since early indication for theformat using the length field of the EHT PPDU cannot be performed, theformat indication bit(s) may be included in the EHT-SIG1 to indicate theformat.

B-ii)-2. Information indicated based on the size of the formatindication bit(s) may be set differently.

B-ii)-2-a. For example, the format indication bit(s) may be set to 2bits. Format indication bit(s) may be used for four format indications.

For example, when the Format indication bit(s) is set to ‘00’, theformat indication bit(s) may indicate the SU PPDU. Alternatively, whenthe format indication bit(s) is set to ‘00’, the EHT PPDU may be set tothe SU PPDU.

As an example, when the format indication bit(s) is set to ‘01’, theformat indication bit(s) may indicate an extended range (ER)-SU PPDU.Alternatively, when the format indication bit(s) is set to ‘01’, the EHTPPDU may be set to the ER-SU PPDU.

For example, when the format indication bit(s) is set to ‘10’, theformat indication bit(s) may indicate a Trigger based (TB) PPDU.Alternatively, when the format indication bit(s) is set to ‘10’, the EHTPPDU may be set to a TB PPDU.

For example, when the format indication bit(s) is set to ‘11’, theformat indication bit(s) may indicate the MU PPDU. Alternatively, whenthe format indication bit(s) is set to ‘11’, the EHT PPDU may be set tothe MU PPDU.

B-ii)-2-b. For example, the Format indication bit(s) may be set to 3bits. Format indication bit(s) may be used for an indication for a newlydefined format in the four format indication (format indication) andfuture version.

B-ii)-2-c. According to an embodiment, one unified PPDU format may beused for SU or MU. In this case, the Format indication bit(s) mayinclude information (or indication information) regarding theconfiguration of EHT-SIG2 or EHT-SIG3 transmitted/received afterEHT-SIG1. For example, if the Format indication bit(s) is set toindicate SU, the SIG3 contiguous to the SIG1 may be configured not toinclude a user specific field.

B-iii) Information related to bandwidth (BW)

B-iii)-1. Information related to a bandwidth (BW) may be used toindicate a bandwidth of 20 MHz to 320 MHz. In other words, informationrelated to the bandwidth (BW) may include information for indicating abandwidth of 20 MHz to 320 MHz. Information related to the bandwidth(BW) may also indicate a bandwidth to which preamble puncturing isconsidered/applied. In other words, information related to the bandwidth(BW) may include information for indicating a bandwidth to whichpreamble puncturing is considered/applied.

B-iii)-2. In consideration of a bandwidth to which preamble puncturingis applied (or to which preamble puncturing is applied), informationrelated to the bandwidth (BW) may has a size of one of 4 to 6 bits.

B-iii)-3. Unlike the above-described embodiment, the bandwidth may beindicated in the EHT-SIG1 and EHT-SIG2/3, respectively. In other words,the bandwidth-related information may be included in the EHT-SIG1 andEHT-SIG2/3.

For example, the EHT-SIG1 may indicate whether the EHT PPDU istransmitted over a wide bandwidth. In other words, the EHT-SIG1 mayinclude information related to whether the EHT PPDU is transmitted overa wide bandwidth. As an example, the EHT-SIG1 may include informationrelated to whether a bandwidth of the EHT PPDU is 160 MHz or more (or240, 320 MHz or more). In addition, information related to a specificbandwidth may be included in the EHT-SIG2 or EHT-SIG3.

For example, the first information related to the bandwidth included inthe EHT-SIG1 may indicate whether the EHT PPDU is transmitted over awide bandwidth (wide bandwidth). Information related to the bandwidthincluded in the EHT-SIG1 may consist of 1 or 2 bits. The secondinformation related to the bandwidth included in the EHT-SIG2 orEHT-SIG3 may be configured with 4 or 5 bits in consideration of multipleRUs and preamble puncturing.

B-iv) Information Related to Functionality/Mode Indication

Information related to the functionality/mode indication may beconfigured as 1 or 2 bits. Specifically, the information related to thefunctionality/mode indication may include information related to thefunctionality/mode used for transmission of the EHT PPDU. Informationrelated to the functionality/mode indication may be used to indicateHARQ, multilink, and/or multi-AP transmission.

B-v) Tail Bits

Tail bits may consist of 6 bits.

B-vi) CRC Bits

CRC bits may consist of 4 bits.

B-vii) Information Related to MCS of EHT-SIG3

B-vii)-1. When the same format is used for SU/MU transmission, or whenan MU PPDU (i.e., a PPDU in which EHT-SIG1 is transmitted followed byEHT-SIG3) is transmitted, information related to the MCS of EHT-SIG3 maybe included in the U-SIG (or EHT-SIG1).

B-vii)-2. Information related to the MCS of the EHT-SIG3 may be used toindicate various MCSs applied to the EHT-SIG3. In other words,information related to the MCS of the EHT-SIG3 may include informationrelated to various MCSs applied to the EHT-SIG3. For example,information related to the MCS of the EHT-SIG3 may be configured/definedwith 2 to 3 bits. As an example, the available MCS may be set to MCS0 toMCSS.

B-viii) Information Related to Dual Carrier Modulation (DCM) of EHT-SIG3

The information related to the MCS of the EHT-SIG3 may indicate whetherthe DCM is used/applied to the EHT-SIG3. In other words, the informationrelated to the MCS of the EHT-SIG3 may include information related towhether DCM is used/applied to the EHT-SIG3.

B-ix) Remaining bits other than the above-described information in theEHT-SIG1 may be composed of at least some or all of information fieldsdefined in HE-SIGA of the conventional 802.11ax standard.

B-ix)-1. 11Ax HE-SIGA Field in SU Case

For SU case, the flax HE-SIGA field may include various information(fields). For example, in the SU case, 11ax HE-SIGA field may includeinformation related to: beam change; MCS; DCM; spatial reuse; GI+LTF;NSTS and MP; Coding; LDPC Extra symbol; STBC; Beamformed; Pre-FECpadding; PE Disambiguity and/or doppler.

B-ix)-2. 11Ax HE-SIGA Field in MU Case

For MU case, the flax HE-SIGA field may include various information(fields). For example, in MU case, the flax HE-SIGA field may includeinformation related to: SIGB-MCS; SIGB-DCM; SR; Number of SIGB symbolsor MU-MIMO users; SIB compression; GI+LTF; Doppler; number of LTFsymbols and MP; LDPC Extra symbol; STBC; Pre-FEC padding; and/or PEDisambiguity.

B-ix)-3. 11Ax HE-SIGA Field in ER-SU Case

For ER-SU case, the flax HE-SIGA field may include various information(fields). For example, in the ER-SU case, the flax HE-SIGA field mayinclude information related to: beam change; MCS; DCM; spatial reuse;GI+LTF; NSTS and MP; Coding; LDPC Extra symbol; STBC; Beamformed;Pre-FEC padding; PE Disambiguity; and/or doppler.

B-ix)-4. 11Ax HE-SIGA Field in TB Case

For TB case, the flax HE-SIGA field may include information related toSR1, SR2, SR3, and/or SR4.

2. EHT-SIG2 Configuration

A. The EHT-SIG2 may be configured based on a combination of information(fields) included in the HE-SIGA of 802.11ax standard. For example, thecombination of information (fields) included in HE-SIGA of the 802.11axstandard may consist of information not included in the EHT-SIG1.

B. EHT-SIG2 may include CRC bits (4 bits) and tail bits (6 bits).

C. EHT-SIG2 may include allocation information for allocating resourcesfor multiple RUs, multiple BWs and/or preamble puncturing for a singleuser (SU).

C-i) The allocation information may be configured as 8 bits (or 8-bittable). The configuration of the allocation information in the 8-bittable is exemplary and may be configured in various ways. For example,in consideration of signaling overhead, the allocation information maybe configured with 4 or 6 bits (or 4 or 6 bit tables).

C-ii) Considering that different NSSs are used, information related toNSS may be further included in the EHT-SIG2.

D. Unlike the above-described “C”, the EHT-SIG2 may include RUallocation information for OFDMA transmission. In this case, theEHT-SIG2 may consist of 1 or 2 symbols.

D-i) Information included in the common field of the HE-SIGB of the802.11 standard (e.g., information related to NSTS and RU allocation)may be included in the EHT-SIG2 and may be transmitted through theEHT-SIG2.

E. Common control information (e.g., version dependent information) notincluded in the EHT-SIG1 and information related to a STA (e.g., commonfield information) may be included in the EHT-SIG2. In other words,common control information overflowed from the EHT-SIG1 may be includedin the EHT-SIG2. The common control information may include informationrelated to transmission of the EHT PPDU. In addition, the EHT-SIG2 mayinclude information related to the STA. Among the information related tothe STA, common field information may include (RU) allocationinformation.

F. The format indication bit included in the EHT-SIG1 may be transmittedthrough the EHT-SIG2.

G. The EHT-SIG2 may include an indication bit for transmissiongranularity of the EHT-SIG3 including user information. In other words,the EHT-SIG2 may include information related to the transmissiongranularity of the EHT-SIG3 including User information.

G-i) For example, the granularity of the EHT-SIG3 may be set based ontwo granularities. In this case, the EHT-SIG3 channel may be configuredin units of 20 MHz or 40 MHz.

G-ii) The 40 MHz granularity may be used when transmitting a largebandwidth (e.g., 240M Hz or 320 MHz).

H. The EHT-SIG2 may be transmitted based on MCS0 or various MCS (variousMCS).

3. EHT-SIG3 Configuration

A. The EHT-SIG3 may be configured to include the same information as theHE-SIGB described below. That is, the EHT-SIG3 may include a commonfield and a user specific field. The user specific field may beconfigured based on at least a part of information of the user fielddescribed below.

A-i) Flax HE-SIGB Field for OFDMA

The EHT-SIG3 may include at least some or all of information (fields)included in the 11ax HE-SIGB field for OFDMA. For example, the EHT-SIG3may include information related to STA-ID, NSTS, beamformed, MCS, DCMand/or Coding.

A-ii) Flax HE-SIGB Field for MU-MIMO

The EHT-SIG3 may include at least some or all of information (fields)included in the flax HE-SIGB field for MU-MIMO. For example, theEHT-SIG3 may include information related to STA-ID, SpatialConfiguration, MCS, and/or Coding.

A-iii) The EHT-SIG3 may be configured to include information related tomultiple RU allocation in addition to the above information.

B. The EHT-SIG3 may be included in an EHT PPDU (or EHT frame) whentransmitting a signal to multiple STAs. In addition, the EHT-SIG3 may beincluded in MU PPDU transmission to configure a PPDU (i.e., EHT PPDU).

C. Unlike the above example, the SU/MU PPDU may be formed/configured ina unified PPDU format. In this case, the EHT-SIG3 may be transmittedwhile being included in a PPDU (i.e., EHT PPDU) even during SUtransmission.

C-i) For SU transmission, the EHT-SIG3 may be configured only with acommon field, unlike the MU transmission.

C-ii) The common field may be configured as version dependentinformation and common information bits. Also, the common field may beencoded including one CRC field and one tail bit field. For example, theversion dependent information may be configured as common controlinformation not included in the EHT-SIG1 (e.g., U-SIG).

C-iii) Even for SU transmission, various MCSs (various MCSs) may beapplied to the EHT-SIG (e.g., EHT-SIG3). Indication related to the MCSof the EHT-SIG3 may be performed in the EHT-SIG1. In other words,information related to the MCS of the EHT-SIG3 may be included in theEHT-SIG1.

C-iv) Also, size information for the EHT-SIG (e.g., EHT-SIG3) may beindicated through the EHT-SIG1. For example, the number of OFDM symbolsused for the EHT-SIG (e.g., EHT-SIG3) may be indicated through theEHT-SIG1. In other words, size information for the EHT-SIG (e.g.,EHT-SIG3) may be included in the EHT-SIG1. For example, informationrelated to the number of OFDM symbols used in the EHT-SIG (e.g.,EHT-SIG3) may be included in the EHT-SIG1.

D. According to an embodiment, the EHT-SIG may include the EHT-SIG1,EHT-SIG2 and EHT-SIG3. When the EHT-SIG2 includes allocation informationincluded in the common field, EHT-SIG3 may be configured with theremaining information except for the allocation information.

D-i) For example, the EHT-SIG3 may be configured only with user specificinformation excluding the common field of the HE-SIGB.

E. According to an embodiment, the EHT-SIG3 may include a common fieldand a user specific field. The common field and the user specific fieldmay include CRC bit(s) and tail bit(s), respectively, and may beseparately/individually encoded.

F. According to an embodiment, the EHT-SIG3 may be configured to includeinformation (e.g., version dependent information) of the EHT-SIG2. Inother words, the EHT-SIG3 may include at least a part or all ofinformation (fields) included in the EHT-SIG2.

For example, information included in the EHT-SIG2 may be included in acommon field of the EHT-SIG3. In addition, in order to reduce signalingoverhead, one CRC field and one tail bit field may be applied (andjointly encoded) to information of EHT-SIG2 and information of thecommon field, thereby configuring the common field. In other words, inaddition to the common field, information included in the EHT-SIG2 maybe further included. The common field may be jointly encoded with oneCRC field and one tail bit field.

According to an embodiment, the EHT PPDU may include a first signalfield and a second signal field. For example, the first signal field mayinclude U-SIG. The U-SIG may include the above-described EHT-SIG1.

For example, the second signal field may include EHT-SIG. The EHT-SIGmay include the common field and the user specific field. The commonfield may be called by various names. The common field may be referredto as a transmission information field.

As an example, the EHT-SIG may include the above-described EHT-SIG2 andEHT-SIG3. The common field may include the EHT-SIG2. The user specificfield may include the EHT-SIG3.

As another example, when the EHT-SIG3 includes all of theabove-described information (fields) of the EHT-SIG2, the EHT-SIG mayinclude the EHT-SIG3. The EHT-SIG3 may be configured as the common fieldand the user specific field.

Configuration of EHT PPDU

The above-described EHT-SIG (e.g., EHT-SIG1, EHT-SIG2, EHT-SIG3) may beapplied to configure an EHT PPDU. The EHT PPDU may be configured invarious formats. For example, the EHT PPDU may be configured in an SUPPDU format, an MU PPDU format, an ER SU PPDU format, and/or a TB PPDUformat. Hereinafter, the configuration of the SU PPDU format, the MUPPDU format, the ER SU PPDU format, and the TB PPDU format may besequentially described.

Configuration of SU PPDU Format

A. The SU PPDU may be a format of a PPDU transmitted to a single user.For example, the SU PPDU may be configured as shown in FIG. 22 .

FIG. 22 shows an example of the configuration of an SU PPDU.

Referring to FIG. 22 , the SU PPDU 2200 may include EHT-SIG1 2210 andEHT-SIG2 2220. For example, the same MCS may be applied to the EHT-SIG12210 and the EHT-SIG2 2220 for transmission of the SU PPDU 2200. Asanother example, various MCSs may be applied to the EHT-SIG2 2220 fortransmission of the SU PPDU 2200.

B. Unlike FIG. 22 , the SU PPDU may include EHT-SIG3 for MU transmissionin order to support multiple RU aggregation and preamble puncturingtransmission. That is, SU transmission may be performed using the MUPPDU. In this case, a single PPDU for SU/MU transmission may beconfigured. An example of a PPDU for SU/MU transmission may be describedwith reference to FIG. 23 .

FIG. 23 shows another example of the configuration of an SU PPDU.

Referring to FIG. 23 , the SU PPDU 2300 may be used not only fortransmission for a single user (SU), but also for transmission for amulti user (MU). The SU PPDU 2300 may include EHT-SIG1 2310 and EHT-SIG32330.

B-i) The EHT-SIG3 2330 may consist of a common field and a user field.The user field may be configured to include the same STA ID for multipleRU aggregation. When transmitting through preamble puncturing, theEHT-SIG3 2330 may be configured to include only one user field. That is,even when the EHT PPDU is transmitted to a single user, the user fieldmay be included in the EHT-PPDU for transmission.

B-ii) In an embodiment different from B-i), the EHT-SIG3 2330 may beconfigured to include only a common field. For example, the common fieldmay include version dependent information, information related to Nsts,and/or information related to RU allocation.

B-ii)-1. The information related to the RU allocation may includeallocation information for multiple RUs and/or preamble puncturing.

B-ii)-2. The common field may be encoded including one CRC field and onetail bit field.

B-iii) When one PPDU format is used to support both SU and MU, whetherSU/MU is supported may be indicated through the PPDU format indicationtransmitted through the EHT-SIG1. In other words, information related towhether SU/MU is supported may be included in the PPDU format indicationof the EHT-SIG1. In other words, the receiving STA may check whether thereceived EHT PPDU is a PPDU for SU or MU based on the PPDU formatindication of the EHT-SIG1.

B-iv) In addition, the receiving STA may confirm/check that EHT-SIG3 isconfigured differently through the PPDU format indication. In otherwords, the receiving STA may confirm/check whether SU transmission andMU transmission are applied based on the PPDU format indication, and thereceiving STA may confirm/check that the EHT-SIG3 is configureddifferently based on the PPDU format indication.

B-v) According to an embodiment, the transmission method of the EHT-SIG3may be set differently according to SU/MU transmission. For example, inSU transmission, when the EHT-SIG3 is transmitted through a bandwidth of20 MHz or more, it may be transmitted by being duplicated in units of 20MHz (or 40 MHz). In MU transmission, the EHT-SIG3 may beseparately/individually configured with two 20 MHz, and then duplicatedin units of 40 MHz for transmission. Accordingly, the PPDU formatindication bit may indicate SU/MU classification, EHT-SIG3 configurationof the PPDU, and transmission method of the EHT-SIG3. In other words,the PPDU format indication bit may include information for SU/MUclassification, information related to the EHT-SIG3 configuration of thePPDU, and information related to the transmission method of theEHT-SIG3.

Configuration of MU PPDU Format

A. The MU PPDU may be a format of a PPDU transmitted to multiple users.For example, the MU PPDU may be configured as shown in FIG. 24 .

FIG. 24 shows an example of the configuration of an MU PPDU.

Referring to FIG. 24 , the MU PPDU 2400 may include EHT-SIG1 2410,EHT-SIG2 2420, and EHT-SIG3 2430.

A-i) The EHT-SIG2 2420 and EHT-SIG3 2430 may be transmitted by applyingvarious MCSs. Information related to the MCS(s) of EHT-SIG2 2420 andEHT-SIG3 2430 may be indicated through bits of the EHT-SIG1 2410 andEHT-SIG2 2420, respectively. In other words, information related to theMCSs of EHT-SIG2 2420 and EHT-SIG3 2430 may be included in the EHT-SIG12410 and EHT-SIG2 2420, respectively. For example, information relatedto the MCS of the EHT-SIG2 2420 may be included in the EHT-SIG1 2410.Information related to the MCS of the EHT-SIG3 2430 may be included inthe EHT-SIG2 2420.

A-ii) Unlike the above-described example (A-i), the EHT-SIG1 2410 andEHT-SIG2 2420 may be commonly modulated based on ‘MCS0’. In other words,the EHT-SIG1 2410 and EHT-SIG2 2420 may each be modulated based on theMCS0.

B. Unlike FIG. 24 described above, the MU PPDU may be configured toinclude the EHT-SIG1 and EHT-SIG3. That is, unlike FIG. 24 , theEHT-SIG2 may be omitted from the MU PPDU. An example in which theEHT-SIG2 is omitted in the MU PPDU may be described with reference toFIG. 25 .

FIG. 25 shows another example of the configuration of an MU PPDU.

Referring to FIG. 25 , the MU PPDU 2500 may include EHT-SIG1 2510 andEHT-SIG3 2530. The EHT-SIG3 2530 may include a common field 2531 and auser specific field 2533. For example, the EHT-SIG3 2530 may includeinformation (e.g., version dependent bits) included in the EHT-SIG2described above. The information included in the above-described theEHT-SIG2 may be included in the common field 2531 of the EHT-SIG3 2530for transmission.

B-i) For example, one CRC field and one tail bit field may be applied toconfigure the common field 2531. That is, the common field 2531 mayinclude version dependent bits, common bits, CRC and tail (or tailbits).

As another example, the common field 2531 may be configured by applyingeach of the CRC field and tail field to version dependent information(or version dependent bits) and common bits in the common field 2531.That is, the common field 2531 may include version dependent bits, CRCfor the version dependent bits, tail for the version dependent bits,common bits, CRC for the common bits, and tail for the common bits.

Configuration of TB PPDU Format

The TB PPDU may be a format of a PPDU transmitted in response to atrigger frame. For example, the TB PPDU may be configured as shown inFIG. 26 or FIG. 27 .

FIG. 26 shows an example of the configuration of a TB PPDU.

A. Referring to FIG. 26 , TB PPDU 2600 may be configured in the sameformat as the SU PPDU 2200 illustrated in FIG. 22 . For example, the TBPPDU 2600 may include EHT-SIG1 2610 and EHT-SIG2 2620. The TB PPDU 2600may include information related to the SR included in the HE-SIGA of the802.11ax standard.

FIG. 27 shows another example of the configuration of a TB PPDU.

B. Referring to FIG. 27 , unlike FIG. 26 , TB PPDU 2700 may include onlyEHT-SIG1 2710 among the above-described EHT-SIGs (e.g., EHT-SIG1,EHT-SIG2 and EHT-SIG3).

The EHT-SIG1 2710 may include information related to a PHY identifier,format indication, BW and/or DL/UL, etc. as defined above. In addition,the EHT-SIG1 2710 may further include at least some or all ofinformation (fields) included in the HE-SIGA of the TB PPDU of the802.11ax standard.

According to an embodiment, the EHT-SIG1 2710 may consist of 2 symbols.In this case, the EHT-SIG1 2710 may not be enough to include newinformation (or new contents). For example, the new information mayinclude information other than information included in the HE-SIGA ofthe TB PPDU of the 802.11ax standard.

Accordingly, in order to secure bits for new information, someinformation (or some contents) included in HE-SIGA may be excluded toconfigure EHT-SIG1 2710. For example, the EHT-SIG1 2710 may not includeSR information (or information bits) among information included inHE-SIGA of the TB PPDU of the 802.11ax standard.

Configuration of ER SU PPDU Format

A. The ER SU PPDU may be a format of a PPDU used for range extension. Inthis case, the SIG field may be repeatedly transmitted to improvereliability of the SIG field. In addition, during ER-SU transmission, anL-STF and an L-LTF may be transmitted with 3 dB boosting. The ER SU PPDUmay include the U-SIG.

B. In order to speed up the confirmation/recognition of the frame type,the U-SIG (e.g., EHT-SIG1) included in the ER SU PPDU may consist of onesymbol, and the U-SIG may be repeatedly transmitted.

B-i) For example, the U-SIG may consist of 1 symbol. The U-SIG may beconfigured based on of a combination of the following information(fields).

B-i)-1. Information Related to the PHY Version Identifier

Information related to the PHY version identifier may consist of 3 bits.

B-i)-2. Information Related to Frame Format

Information related to the frame format may be used to indicate the PPDUformat. The frame format may include a format of SU/MU/TB/ER (ER SU). Inaddition, the information related to the frame format may be set to 2 or3 bits in consideration of the future PPDU type.

B-i)-3. Information Related to BSS Color

For example, information related to the BSS color may be configured as 6bits similar to 802.11ax. For another example, the information relatedto the BSS color may be set to a size larger than 6 bits in order toclarify the identification of the BSS. For example, 7/8/9/10 bits, etc.may be used for the information related to the BSS color.

B-i)-4. Information related to TXOP

B-i)-5. Tail (or Tail bits)

The tail bits may be set to 6 bits.

B-i)-6. CRC

The CRC (or CRC bits) may be set to 4 bits.

B-ii) As in the above-described embodiment, the U-SIG may consist of onesymbol. Accordingly, for SU transmission, among subfields included inthe U-SIG, a subfield not included in one symbol U-SIG may betransmitted though the EHT-SIGA (e.g., EHT-SIG2). In this case, theEHT-SIGA may consist of 1 or 2 symbols.

B-ii)-a. For example, the EHT-SIGA consisting of 2 symbols may betransmitted as follows for repetition. Hereinafter, notation of “H” maymean one symbol.

B-ii)-a-i) [EHT-SIGA1 and EHT-SIG2] [EHT-SIGA1 and EHT-SIG2]

The EHT-SIGA repeated in “B-ii)-a-i)” can be formed/configured bybypassing an interleaver.

B-ii)-a-ii) [EHT-SIGA1 and EHT-SIG1] [EHT-SIGA2 and EHT-SIG2]

C. An example of an ER SU PPDU including a SIG field according to theabove-described embodiment may be described with reference to FIG. 28 .

FIG. 28 shows an example of the configuration of an ER SU PPDU.

Referring to FIG. 28 , ER SU PPDU 2800 may include L-STF 2801, L-LTF2802, L-SIG 2803, RL-SIG 2804, U-SIG 2805, RU-SIG 2806, EHT-SIGA 2807,REHT-SIGA 2808, EHT-STF 2809, EHT-LTF 2810, and DATA 2811. For example,the U-SIG 2805 may consist of 1 symbol. The EHT-SIGA 2807 may consist of2 symbols. As an example, the RU-SIG 2806 may be configured by repeatingthe U-SIG 2805. For example, the REHT-SIGA 2808 may be configured byrepeating the EHT-SIGA 2807.

D. Unlike the above-described embodiment, the U-SIG (e.g., EHT-SIG1) mayconsist of 2 symbols. The U-SIG configured as the two symbols may berepeated in various ways. An example in which the U-SIG composed of thetwo symbols is repeated may be described below.

D-i) For example, since the U-SIG is composed of two symbols, U-SIG maybe composed of U-SIG1 and U-SIG2. The U-SIG1 may be transmitted byincluding information related to the PHY identification and frame formatindicator. The U-SIG1 can be configured by bypassing an interleaver inorder to quickly acquire information related to the PHY identify andframe format indicator. And, the U-SIG2 can be configured by applying aninterleaver.

D-ii) Configuration of U-SIG for ER SU PPDU

D-ii)-1. For example, the U-SIG may be configured in the order of theU-SIG1 (first symbol), repeated U-SIG1, U-SIG2 (second symbol), andrepeated U-SIG2.

D-ii)-2. For example, the U-SIG may be configured in the order of theU-SIG1, U-SIG2, repeated U-SIG1, and repeated U-SIG2.

The repeated U-SIG1 or repeated U-SIG2 in D-ii)-1 and D-ii)-2 can beconfigured by bypassing an interleaver.

E. The ER SU PPDU according to the above-described embodiment may beconfigured as shown in FIG. 29 or FIG. 30 .

FIG. 29 shows another example of the configuration of an ER SU PPDU.

Referring to FIG. 29 , ER SU PPDU 2900 may include L-STF, L-LTF, L-SIG,RL-SIG, U-SIG, RU-SIG, EHT-SIG, REHT-SIG, EHT-STF, EHT-LTF, and DATA.The U-SIG may consist of 2 symbols. The RU-SIG may be configured byrepeating the U-SIG. The REHT-SIG may be configured by repeating theEHT-SIG.

FIG. 30 shows another example of the configuration of an ER SU PPDU.

Referring to FIG. 30 , ER SU PPDU 3000 may include L-STF, L-LTF, L-SIG,RL-SIG, U-SIG, RU-SIG, A-SIG, RA-SIG, EHT-STF, EHT-LTF, and DATA. Forexample, the A-SIG may consist of 1 symbol. The A-SIG may include atleast a portion of the EHT-SIG of FIG. 29 . In addition, the A-SIG mayfurther include additional information for the extended range. TheRA-SIG may be configured by repeating the A-SIG.

FIG. 31 is a flowchart for explaining an operation of a transmittingSTA.

Referring to FIG. 31 , in step S3110, the transmitting STA may generatea PPDU. For example, the PPDU may include an EHT PPDU.

According to an embodiment, the PPDU may include a first signal fieldand a second signal field.

For example, the first signal field and the second signal field may berespectively encoded. As an example, in the first signal field, twosymbols may be jointly encoded. In addition, the first signal field andthe second signal field may be modulated, respectively.

For example, the first signal field may include the U-SIG. For example,the second signal field may include the EHT-SIG.

According to an embodiment, the PPDU may further include an L-SIG fieldand a RL-SIG field. For example, the RL-SIG field may be contiguous tothe L-SIG field. For example, the first signal field may be contiguousto the RL-SIG field. For example, the second signal field may becontiguous to the first signal field.

For example, the transmitting STA may set a value of a length field ofthe L-SIG field based on a transmission time of the PPDU. As an example,a result of ‘modulo 3’ operation for the value of the length field ofthe L-SIG field may be set to zero (0).

For example, the RL-SIG field may be configured such that the L-SIGfield is repeated. For example, the RL-SIG field includes the sameinformation field as the L-SIG field, and may be modulated in the samemanner. The L-SIG field and the RL-SIG field may be modulated throughBPSK, respectively.

According to an embodiment, the first signal field may include firstinformation related to a version of the PPDU. The first information maybe determined based on whether the PPDU is an EHT PPDU.

For example, the first information related to a Physical Layer (PHY)version of the PPDU may be configured as 3-bit information. The firstinformation may include information indicating that the PPDU is a PPDU(i.e., an EHT PPDU) based on the EHT standard. In addition, the firstinformation may include information for classifying a PPDU according toa new standard defined after the 802.11be standard (i.e., the EHTstandard). In other words, the first information may include informationfor classifying a PPDU based on an EHT standard and a PPDU based on astandard determined/generated/established after the EHT standard. Thatis, the first information may include information indicating that thePPDU is a PPDU in compliance with an EHT standard or a PPDU incompliance with the EHT standard.

According to an embodiment, the type of the PPDU and the version of thePPDU may be used separately. The type of PPDU may be used to classifythe PPDU according to the EHT standard and the standard before the EHTstandard (e.g., 802.11n/ac/ax). On the other hand, the version of thePPDU may be used to distinguish the PPDU according to the EHT standardand the standard after the EHT standard. For example, the version of thePPDU may be called variously. For example, the version of the PPDU maybe referred to as a PHY version, a Packet version, a Packet identifier,and a Wi-Fi version.

According to an embodiment, the first signal field may further includeinformation related to a basic service set (BSS) color and informationrelated to a transmission opportunity (TXOP). For example, theinformation related to the BSS color may be set as various bitinformation. As an example, the information related to the BSS color maybe set as 6-bit information. For example, the information related to theTXOP may be set to various bit information. As an example, informationrelated to TXOP may be set as 7-bit information.

According to an embodiment, the first signal field may include at leastone of: information related to whether Hybrid Automatic Repeat Request(HARQ) is applied to the PPDU; information related to whether multi-linktransmission is applied to the PPDU; and information related to whethermulti-access point (multi-AP) transmission is applied to the PPDU.

According to an embodiment, the second signal field may include secondinformation which is related to transmission of the PPDU which isconfigured based on the first information. The second information may bereferred to by various names. For example, the second information may bereferred to as version dependent information.

For example, the second information may include transmission informationdependent on a version of the PPDU. In other words, the configuration ofinformation included in the second information may be set differentlybased on the version of the PPDU. For example, when the version of thePPDU corresponds to the EHT standard (i.e., when the PPDU is an EHTPPDU), the second information may include at least one of: informationrelated to a size of a long training field (LTF); information related toa number of symbols of the LTF; information related to a Low DensityParity Check Code (LDPC) extra symbol; information related to apre-forward error correction (FEC) padding factor; and informationrelated to a packet extension (PE).

For example, the second information may include overflow informationoverflowed from the first signal field. For example, the first signalfield may include information independent of the version of the PPDU andinformation dependent on the version of the PPDU. Information dependenton the version of the PPDU may be included in the second signal field bybeing overflowed from the first signal field.

According to an embodiment, the second signal field may include a commonfield and a user specific field. The common field may be called byvarious names. The common field may be referred to as a transmissioninformation field. For example, the second information may be includedin the common field. The common field may further include commoninformation related to the user (e.g., information related to RUallocation). In other words, the common field may include information(e.g., second information) related to transmission of the PPDU. Inaddition, the common field may further include common informationrelated to the user (e.g., information related to RU allocation) inaddition to information related to PPDU transmission (e.g., secondinformation).

For example, the second signal field may be configured for multipleusers. The user specific field may include information related tomultiple users. As an example, the user specific field may includeinformation necessary for each multi-user. When the multi-user includesthe first user and the second user, the user specific field may includea subfield for the first user and a subfield for the second user.

For another example, the second signal field may be configured for asingle user. For example, when the PPDU is transmitted for a singleuser, the second signal field may be configured for a single user. As anexample, the second signal field may be configured to be duplicated inunits of 20 MHz. In other words, the second signal field may beconfigured by being duplicated in units of 20 MHz within the bandwidthof the PPDU. That is, when the PPDU is transmitted for a single user,the second signal field may be repeatedly configured in units of 20 MHz.In other words, based on the PPDU being configured/transmitted for asingle user, the second signal field may be repeatedlyconfigured/transmitted in units of 20 MHz.

For example, even when the PPDU is transmitted for a single user, thesecond signal field may include a common field and a user specificfield. However, when the PPDU is transmitted for a single user, detailedfield values of the common field and the user specific field may bechanged.

As an example, the user specific field may be configured to include thesame STA-ID. As another example, the user specific field may includeonly a subfield for a single user. As another example, the common fieldof the second signal field may include information indicating that thesecond signal field is configured for a single user.

For example, each of a common field and a user-specific field may beseparately/individually encoded. As an example, the common field mayinclude first cyclic redundancy check (CRC) bits and first tail bits forthe common field. As an example, the user-specific field may includesecond CRC bits and second tail bits related to the user-specific field.

For example, the user specific field may be configured based on whetherOrthogonal Frequency Division Multiplexing Access (OFDMA) or MultiUser-Multiple Input Multiple Output (MU-MIMO) is applied. For example,when the OFDMA is applied, the user specific field may includeinformation related to STA-ID (identifier), information related tonumber of space-time streams (NSTS), information related to whetherbeamforming is performed, information related to MCS, informationrelated to whether Dual Carrier Modulation (DCM) is applied, andinformation related to coding. As another example, when the MU-MIMO isapplied, the user specific field may include information related toSTA-ID (identifier), information related to Spatial Configuration,information related to MCS, and information related to coding.

In step S3120, the transmitting STA may transmit a PPDU. According to anembodiment, each field included in the PPDU may be transmitted through asymbol. For example, the L-SIG field may be transmitted through thefirst symbol. The RL-SIG field may be transmitted through a secondsymbol contiguous to the first symbol. The first signal field may betransmitted through a third symbol contiguous to the second symbol. Thesecond signal field may be transmitted through a fourth symbolcontiguous to the third symbol.

As an example, the first symbol may consist of one symbol. The secondsymbol may consist of one symbol. The third symbol may consist of twosymbols. Accordingly, the first signal field may be transmitted throughtwo symbols. For example, the fourth symbol may consist of at least oneor more symbols. Accordingly, the second signal field may be transmittedthrough at least one or more symbols contiguous to the two symbolsthrough which the first signal field is transmitted.

FIG. 32 is a flowchart illustrating an operation of a receiving STA.

Referring to FIG. 32 , in step S3210, a receiving STA may receive aPPDU.

According to an embodiment, the PPDU may include a first signal fieldand a second signal field.

For example, the first signal field and the second signal field may berespectively encoded. As an example, in the first signal field, twosymbols may be jointly encoded. In addition, the first signal field andthe second signal field may be modulated, respectively.

For example, the first signal field may include the U-SIG. For example,the second signal field may include the EHT-SIG.

According to an embodiment, the PPDU may further include an L-SIG fieldand a RL-SIG field. For example, the RL-SIG field may be contiguous tothe L-SIG field. For example, the first signal field may be contiguousto the RL-SIG field. For example, the second signal field may becontiguous to the first signal field.

According to an embodiment, each field included in the PPDU may bereceived through a symbol. For example, the L-SIG field may be receivedthrough the first symbol. The RL-SIG field may be received through asecond symbol contiguous to the first symbol. The first signal field maybe received through a third symbol contiguous to the second symbol. Thesecond signal field may be received through a fourth symbol contiguousto the third symbol.

As an example, the first symbol may consist of one symbol. The secondsymbol may consist of one symbol. The third symbol may consist of twosymbols. Accordingly, the first signal field may be received through twosymbols. For example, the fourth symbol may consist of at least one ormore symbols. Accordingly, the second signal field may be receivedthrough at least one or more symbols contiguous to the two symbolsthrough which the first signal field is received.

For example, the transmitting STA may set a value of a length field ofthe L-SIG field based on a transmission time of the PPDU. As an example,a result of ‘modulo 3’ operation for the value of the length field ofthe L-SIG field may be set to zero (0).

For example, the RL-SIG field may be configured such that the L-SIGfield is repeated. For example, the RL-SIG field includes the sameinformation field as the L-SIG field, and may be modulated in the samemanner. The L-SIG field and the RL-SIG field may be modulated throughBPSK, respectively.

According to an embodiment, the first signal field may include firstinformation related to a version of the PPDU. The first information maybe determined based on whether the PPDU is an EHT PPDU. The firstinformation may include information related to whether the PPDU is anEHT PPDU. Accordingly, the receiving STA may confirm/check that the PPDUis an EHT PPDU based on the first information.

For example, the first information related to a Physical Layer (PHY)version of the PPDU may be configured as 3-bit information. The firstinformation may include information indicating that the PPDU is a PPDU(i.e., an EHT PPDU) based on the EHT standard. In addition, the firstinformation may include information for classifying a PPDU according toa new standard defined after the 802.11be standard (i.e., the EHTstandard). In other words, the first information may include informationfor classifying a PPDU based on an EHT standard and a PPDU based on astandard determined/generated/established after the EHT standard. Thatis, the first information may include information indicating that thePPDU is a PPDU in compliance with an EHT standard or a PPDU incompliance with the EHT standard.

According to an embodiment, the type of the PPDU and the version of thePPDU may be used separately. The type of PPDU may be used to classifythe PPDU according to the EHT standard and the standard before the EHTstandard (e.g., 802.11n/ac/ax). On the other hand, the version of thePPDU may be used to distinguish the PPDU according to the EHT standardand the standard after the EHT standard. For example, the version of thePPDU may be called variously. For example, the version of the PPDU maybe referred to as a PHY version, a Packet version, a Packet identifier,and a Wi-Fi version.

According to an embodiment, the first signal field may further includeinformation related to a basic service set (BSS) color and informationrelated to a transmission opportunity (TXOP). For example, theinformation related to the BSS color may be set as various bitinformation. As an example, the information related to the BSS color maybe set as 6-bit information. For example, the information related to theTXOP may be set to various bit information. As an example, informationrelated to TXOP may be set as 7-bit information.

According to an embodiment, the first signal field may include at leastone of: information related to whether Hybrid Automatic Repeat Request(HARQ) is applied to the PPDU; information related to whether multi-linktransmission is applied to the PPDU; and information related to whethermulti-access point (multi-AP) transmission is applied to the PPDU.

According to an embodiment, the second signal field may include secondinformation which is related to transmission of the PPDU which isconfigured based on the first information. The second information may bereferred to by various names. For example, the second information may bereferred to as version dependent information.

For example, the second information may include transmission informationdependent on a version of the PPDU. In other words, the configuration ofinformation included in the second information may be set differentlybased on the version of the PPDU. For example, when the version of thePPDU corresponds to the EHT standard (i.e., when the PPDU is an EHTPPDU), the second information may include at least one of: informationrelated to a size of a long training field (LTF); information related toa number of symbols of the LTF; information related to a Low DensityParity Check Code (LDPC) extra symbol; information related to apre-forward error correction (FEC) padding factor; and informationrelated to a packet extension (PE).

For example, the second information may include overflow informationoverflowed from the first signal field. For example, the first signalfield may include information independent of the version of the PPDU andinformation dependent on the version of the PPDU. Information dependenton the version of the PPDU may be included in the second signal field bybeing overflowed from the first signal field.

According to an embodiment, the second signal field may include a commonfield and a user specific field. The common field may be called byvarious names. The common field may be referred to as a transmissioninformation field. For example, the second information may be includedin the common field. The common field may further include commoninformation related to the user (e.g., information related to RUallocation). In other words, the common field may include information(e.g., second information) related to transmission of the PPDU. Inaddition, the common field may further include common informationrelated to the user (e.g., information related to RU allocation) inaddition to information related to PPDU transmission (e.g., secondinformation).

For example, the second signal field may be configured for multipleusers. The user specific field may include information related tomultiple users. As an example, the user specific field may includeinformation necessary for each multi-user. When the multi-user includesthe first user and the second user, the user specific field may includea subfield for the first user and a subfield for the second user.

For another example, the second signal field may be configured for asingle user. For example, when the PPDU is transmitted for a singleuser, the second signal field may be configured for a single user. As anexample, the second signal field may be configured to be duplicated inunits of 20 MHz. In other words, the second signal field may beconfigured by being duplicated in units of 20 MHz within the bandwidthof the PPDU. That is, when the PPDU is transmitted for a single user,the second signal field may be repeatedly configured in units of 20 MHz.In other words, based on the PPDU being configured/transmitted for asingle user, the second signal field may be repeatedlyconfigured/transmitted in units of 20 MHz.

For example, even when the PPDU is transmitted for a single user, thesecond signal field may include a common field and a user specificfield. However, when the PPDU is transmitted for a single user, detailedfield values of the common field and the user specific field may bechanged.

As an example, the user specific field may be configured to include thesame STA-ID. As another example, the user specific field may includeonly a subfield for a single user. As another example, the common fieldof the second signal field may include information indicating that thesecond signal field is configured for a single user.

For example, each of a common field and a user-specific field may beseparately/individually encoded. As an example, the common field mayinclude first cyclic redundancy check (CRC) bits and first tail bits forthe common field. As an example, the user-specific field may includesecond CRC bits and second tail bits related to the user-specific field.

For example, the user specific field may be configured based on whetherOrthogonal Frequency Division Multiplexing Access (OFDMA) or MultiUser-Multiple Input Multiple Output (MU-MIMO) is applied. For example,when the OFDMA is applied, the user specific field may includeinformation related to STA-ID (identifier), information related tonumber of space-time streams (NSTS), information related to whetherbeamforming is performed, information related to MCS, informationrelated to whether Dual Carrier Modulation (DCM) is applied, andinformation related to coding. As another example, when the MU-MIMO isapplied, the user specific field may include information related toSTA-ID (identifier), information related to Spatial Configuration,information related to MCS, and information related to coding.

In step S3220, the receiving STA may decode the PPDU. According to anembodiment, the receiving STA may decode PPDUs based on the first signalfield and the second signal field. In addition, the receiving STA maydecode the first signal field and the second signal field, respectively.

The technical features of the present specification described above maybe applied to various devices and methods. For example, theabove-described technical features of the present specification may beperformed/supported through the apparatus of FIGS. 1 and/or 19 . Forexample, the technical features of the present specification describedabove may be applied only to a part of FIGS. 1 and/or 19 . For example,the technical features of the present specification described above areimplemented based on the processing chip(s) 114 and/or 124 of FIG. 1 ,or implemented based on the processor(s) 111 and/or 121 and thememory(s) 112 and/or 122 of FIG. 1 , or may be implemented based on theprocessor 610 and the memory 620 of FIG. 19 . For example, an apparatusof the present specification may comprise a processor; and a memorycoupled to the processor, wherein the processor is configured to:receive a Physical Layer Protocol Data Unit (PPDU), wherein the PPDUincludes a first signal field and a second signal field, wherein thefirst signal field is transmitted through two symbols, wherein the firstsignal field includes first information related to a Physical layer(PHY) version of the PPDU, wherein the first information is determinedbased on whether the PPDU is an extremely high throughput (EHT) PPDU,wherein the second signal field includes second information which isrelated to transmission of the PPDU configured based on the firstinformation; and decode the PPDU based on the first signal field and thesecond signal field.

The technical features of the present specification may be implementedbased on a CRM (computer readable medium). For example, the CRM proposedby this specification stores instructions that perform operationscomprising: receiving a Physical Layer Protocol Data Unit (PPDU),wherein the PPDU includes a first signal field and a second signalfield, wherein the first signal field is transmitted through twosymbols, wherein the first signal field includes first informationrelated to a Physical layer (PHY) version of the PPDU, wherein the firstinformation is determined based on whether the PPDU is an extremely highthroughput (EHT) PPDU, wherein the second signal field includes secondinformation which is related to transmission of the PPDU configuredbased on the first information; and decoding the PPDU based on the firstsignal field and the second signal field. At least one processor relatedto the CRM in the present specification may be the processor(s) 111and/or 121, or the processing chip(s) 114 and/or 124 of FIG. 1 , or theprocessor 610 of FIG. 19 . Meanwhile, the CRM of the presentspecification may be the memory(s) 112 and/or 122 of FIG. 1 , the memory620 of FIG. 19 , or a separate external memory/storage medium/disk.

The foregoing technical features of the present specification areapplicable to various applications or business models. For example, theforegoing technical features may be applied for wireless communicationof a device supporting artificial intelligence (AI).

Artificial intelligence refers to a field of study on artificialintelligence or methodologies for creating artificial intelligence, andmachine learning refers to a field of study on methodologies fordefining and solving various issues in the area of artificialintelligence. Machine learning is also defined as an algorithm forimproving the performance of an operation through steady experiences ofthe operation.

An artificial neural network (ANN) is a model used in machine learningand may refer to an overall problem-solving model that includesartificial neurons (nodes) forming a network by combining synapses. Theartificial neural network may be defined by a pattern of connectionbetween neurons of different layers, a learning process of updating amodel parameter, and an activation function generating an output value.

The artificial neural network may include an input layer, an outputlayer, and optionally one or more hidden layers. Each layer includes oneor more neurons, and the artificial neural network may include synapsesthat connect neurons. In the artificial neural network, each neuron mayoutput a function value of an activation function of input signals inputthrough a synapse, weights, and deviations.

A model parameter refers to a parameter determined through learning andincludes a weight of synapse connection and a deviation of a neuron. Ahyper-parameter refers to a parameter to be set before learning in amachine learning algorithm and includes a learning rate, the number ofiterations, a mini-batch size, and an initialization function.

Learning an artificial neural network may be intended to determine amodel parameter for minimizing a loss function. The loss function may beused as an index for determining an optimal model parameter in a processof learning the artificial neural network.

Machine learning may be classified into supervised learning,unsupervised learning, and reinforcement learning.

Supervised learning refers to a method of training an artificial neuralnetwork with a label given for training data, wherein the label mayindicate a correct answer (or result value) that the artificial neuralnetwork needs to infer when the training data is input to the artificialneural network. Unsupervised learning may refer to a method of trainingan artificial neural network without a label given for training data.Reinforcement learning may refer to a training method for training anagent defined in an environment to choose an action or a sequence ofactions to maximize a cumulative reward in each state.

Machine learning implemented with a deep neural network (DNN) includinga plurality of hidden layers among artificial neural networks isreferred to as deep learning, and deep learning is part of machinelearning. Hereinafter, machine learning is construed as including deeplearning.

The foregoing technical features may be applied to wirelesscommunication of a robot.

Robots may refer to machinery that automatically process or operate agiven task with own ability thereof. In particular, a robot having afunction of recognizing an environment and autonomously making ajudgment to perform an operation may be referred to as an intelligentrobot.

Robots may be classified into industrial, medical, household, militaryrobots and the like according uses or fields. A robot may include anactuator or a driver including a motor to perform various physicaloperations, such as moving a robot joint. In addition, a movable robotmay include a wheel, a brake, a propeller, and the like in a driver torun on the ground or fly in the air through the driver.

The foregoing technical features may be applied to a device supportingextended reality.

Extended reality collectively refers to virtual reality (VR), augmentedreality (AR), and mixed reality (MR). VR technology is a computergraphic technology of providing a real-world object and background onlyin a CG image, AR technology is a computer graphic technology ofproviding a virtual CG image on a real object image, and MR technologyis a computer graphic technology of providing virtual objects mixed andcombined with the real world.

MR technology is similar to AR technology in that a real object and avirtual object are displayed together. However, a virtual object is usedas a supplement to a real object in AR technology, whereas a virtualobject and a real object are used as equal statuses in MR technology.

XR technology may be applied to a head-mount display (HMD), a head-updisplay (HUD), a mobile phone, a tablet PC, a laptop computer, a desktopcomputer, a TV, digital signage, and the like. A device to which XRtechnology is applied may be referred to as an XR device.

The claims recited in the present specification may be combined in avariety of ways. For example, the technical features of the methodclaims of the present specification may be combined to be implemented asa device, and the technical features of the device claims of the presentspecification may be combined to be implemented by a method. Inaddition, the technical characteristics of the method claim of thepresent specification and the technical characteristics of the deviceclaim may be combined to be implemented as a device, and the technicalcharacteristics of the method claim of the present specification and thetechnical characteristics of the device claim may be combined to beimplemented by a method.

What is claimed is:
 1. A method performed by a receiving station (STA)in a wireless local area network (WLAN) system, the method comprising:receiving a Physical Layer Protocol Data Unit (PPDU), wherein the PPDUincludes a universal signal (U-SIG) field and an extremely highthroughput signal (EHT-SIG) field, wherein the U-SIG field has a lengthof two symbols, wherein the U-SIG field includes first informationrelated to a Physical layer (PHY) version of the PPDU, and the firstinformation has a length of 3 bits, wherein the first information isdetermined based on whether the PPDU is an extremely high throughput(EHT) PPDU, wherein the U-SIG field further includes second informationrelated to whether the PPDU is related to a single user (SU)transmission, wherein the EHT-SIG field for the SU transmission has asingle content channel regardless of a bandwidth of the PPDU, whereinthe single content channel is duplicated in every 20 MHz subchannel,wherein the single content channel includes a common field and a userspecific field; and decoding the PPDU based on the first signal fieldand the second signal field.
 2. The method of claim 1, wherein thesingle content channel includes overflow information overflowed from theU-SIG field.
 3. The method of claim 1, wherein the single contentchannel includes at least one of: information related to a size of along training field (LTF); information related to a number of symbols ofthe LTF; information related to a Low Density Parity Check Code (LDPC)extra symbol; information related to a pre-forward error correction(FEC) padding factor; and information related to a packet extension(PE).
 4. The method of claim 1, wherein the common field furtherincludes information related to resource unit (RU) allocation.
 5. Themethod of claim 1, wherein the common field includes first cyclicredundancy check (CRC) bits and first tail bits, wherein the userspecific field includes second CRC bits and second tail bits.
 6. Themethod of claim 1, wherein the user specific field is configured basedon whether Orthogonal Frequency Division Multiplexing Access (OFDMA) orMulti User-Multiple Input Multiple Output (MU-MIMO) is applied.
 7. Themethod of claim 1, wherein the PPDU further includes an L-SIG field andan RL-SIG field, wherein a result of ‘modulo 3’ operation for a lengthfield value of the L-SIG field is set to zero (0), wherein the RL-SIGfield is a repeat of the L-SIG field.
 8. A method performed by atransmitting station (STA) in a wireless local area network (WLAN)system, the method comprising: generating a Physical Layer Protocol DataUnit (PPDU), wherein the PPDU includes a universal signal (U-SIG) fieldand an extremely high throughput signal (EHT-SIG) field, wherein theU-SIG field has a length of two symbols, wherein the U-SIG fieldincludes first information related to a Physical layer (PHY) version ofthe PPDU, and the first information has a length of 3 bits, wherein thefirst information is determined based on whether the PPDU is anextremely high throughput (EHT) PPDU, wherein the U-SIG field furtherincludes second information related to whether the PPDU is related to asingle user (SU) transmission, wherein the EHT-SIG field for the SUtransmission has a single content channel regardless of a bandwidth ofthe PPDU, wherein the single content channel is duplicated in every 20MHz subchannel, wherein the single content channel includes a commonfield and a user specific field; and transmitting the PPDU.
 9. Themethod of claim 8, wherein the single content channel includes overflowinformation overflowed from the U-SIG field.
 10. The method of claim 8,wherein the single content channel includes at least one of: informationrelated to a size of a long training field (LTF); information related toa number of symbols of the LTF; information related to a Low DensityParity Check Code (LDPC) extra symbol; information related to apre-forward error correction (FEC) padding factor; and informationrelated to a packet extension (PE).
 11. The method of claim 8, whereinthe common field further includes information related to resource unit(RU) allocation.
 12. The method of claim 8, wherein the common fieldincludes first cyclic redundancy check (CRC) bits and first tail bits,wherein the user specific field includes second CRC bits and second tailbits.
 13. The method of claim 8, wherein the user specific field isconfigured based on whether Orthogonal Frequency Division MultiplexingAccess (OFDMA) or Multi User-Multiple Input Multiple Output (MU-MIMO) isapplied.
 14. The method of claim 8, wherein the PPDU further includes anL-SIG field and an RL-SIG field, wherein a result of ‘modulo 3’operation for a length field value of the L-SIG field is set to zero(0), wherein the RL-SIG field is a repeat of the L-SIG field.
 15. Atransmitting station (STA) in a wireless local area network (WLAN)system, comprising: a transceiver transmitting a wireless signal; and aprocessor coupled to the transceiver, wherein processor is adapted to:generate a Physical Layer Protocol Data Unit (PPDU), wherein the PPDUincludes a universal signal (U-SIG) field and an extremely highthroughput signal (EHT-SIG) field, wherein the U-SIG field has a lengthof two symbols, wherein the U-SIG field includes first informationrelated to a Physical layer (PHY) version of the PPDU, and the firstinformation has a length of 3 bits, wherein the first information isdetermined based on whether the PPDU is an extremely high throughput(EHT) PPDU, wherein the U-SIG field further includes second informationrelated to whether the PPDU is related to a single user (SU)transmission, wherein the EHT-SIG field for the SU transmission has asingle content channel regardless of a bandwidth of the PPDU, whereinthe single content channel is duplicated in every 20 MHz subchannel,wherein the single content channel includes a common field and a userspecific field; and transmit the PPDU.
 16. The method of claim 15,wherein the single content channel includes overflow informationoverflowed from the U-SIG field.
 17. The method of claim 15, wherein thesingle content channel includes at least one of: information related toa size of a long training field (LTF); information related to a numberof symbols of the LTF; information related to a Low Density Parity CheckCode (LDPC) extra symbol; information related to a pre-forward errorcorrection (FEC) padding factor; and information related to a packetextension (PE).
 18. The method of claim 15, wherein the common fieldfurther includes information related to resource unit (RU) allocation.19. The method of claim 15, wherein the common field includes firstcyclic redundancy check (CRC) bits and first tail bits, wherein the userspecific field includes second CRC bits and second tail bits.
 20. Themethod of claim 15, wherein the user specific field is configured basedon whether Orthogonal Frequency Division Multiplexing Access (OFDMA) orMulti User-Multiple Input Multiple Output (MU-MIMO) is applied.